Abstract
Background:
The aim of this study was to evaluate the prognostic factors and limitations of anatomic unconstrained shoulder arthroplasty, performed without tuberosity osteotomy, for the treatment of secondary glenohumeral arthritis following posttraumatic cephalic collapse or necrosis of the humeral head, defined as type-1 fracture sequelae.
Methods:
Fifty-five patients with type-1 fracture sequelae treated with anatomic shoulder arthroplasty were included in this retrospective single-center cohort study. All anatomic humeral prostheses were implanted without performing a greater tuberosity osteotomy. Glenoid resurfacing was performed in forty-four patients (80%). Clinical and radiographic analysis was performed at a mean of fifty-two months (range, twenty-four to 180 months) postoperatively.
Results:
Four reoperations (7%) were performed, including two revisions in patients who required glenoid resurfacing because of glenoid erosion after hemiarthroplasty. At the time of the latest follow-up, 93% of patients were satisfied or very satisfied, and the mean Subjective Shoulder Value (SSV) was 81%. There were significant improvements in the mean Constant score (from 32 to 69 points), active anterior elevation (from 88° to 141°), external rotation (from 6° to 34°), and internal rotation (from the buttock to L3). Significantly poorer results were associated with proximal humeral deformity in varus and with fatty infiltration of the rotator cuff muscles. Patients with proximal humeral deformity, specifically varus or valgus malunion of the greater tuberosity, had a mean Constant score that was 10 points lower and active elevation that was almost 20° less than patients with no such deformity. The poorest results were observed in patients with varus malunion.
Conclusions:
Our study confirmed that the outcomes of anatomic shoulder arthroplasty for the treatment of type-1 fracture sequelae are good and predictable when deformation of the proximal humerus is acceptable(i.e., when no greater tuberosity osteotomy is necessary). The results were negatively affected by proximal humeral varus deformity and by fatty infiltration of the rotator cuff on imaging studies. In such cases, reverse shoulder arthroplasty may be more appropriate, especially in elderly patients.
Level of Evidence:
Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
The sequelae of a proximal humeral fracture can cause shoulder pain and functional impairment. Hemiarthroplasty or total shoulder arthroplasty are considered after failure of nonoperative treatment1-3, although the reported results have often been poor and unpredictable4-12. The complex deformity of the proximal aspect of the humerus, destruction of articular cartilage and subchondral bone, malunion or nonunion of the greater tuberosity, and associated soft-tissue contractures make this a challenging problem in shoulder reconstruction. There is little consensus in the literature regarding the optimal surgical treatment, and most reports concern small case series with heterogeneous patient populations, variable underlying pathology, and mixed treatment methods.
The senior author (P.B.) has previously described a radiographic classification of proximal humeral fracture sequelae with the aim of improving the ability of the surgeon to anticipate postoperative results after anatomic shoulder arthroplasty13-15. Four types of fracture sequelae were recognized: posttraumatic cephalic collapse, osteonecrosis, or posttraumatic glenohumeral osteoarthritis (type 1), locked chronic dislocation or fracture-dislocation (type 2), surgical neck nonunion (type 3), and severe tuberosity malunion (type 4). The first two types are secondary to intracapsular, impacted proximal humeral fractures, whereas the other two types are secondary to extracapsular, nonimpacted proximal humeral fractures. An anatomic unconstrained prosthesis can be implanted to treat types 1 and 2 without the need to perform a greater tuberosity osteotomy, as there is only slight and acceptable distortion of the osseous anatomy of the proximal aspect of the humerus and the rotator cuff tends to be functional. In contrast, in types 3 and 4, the results of anatomic shoulder arthroplasty are frequently compromised by the need for a greater tuberosity osteotomy and incompetence of the rotator cuff muscles.
Since 1994, we have followed a treatment algorithm based on this radiographic classification and have used anatomic unconstrained shoulder arthroplasty for the treatment of type-1 and 2 fracture sequelae. Recently, some authors have proposed the use of either surface replacement arthroplasty or reverse shoulder arthroplasty for patients presenting with proximal humeral fracture sequelae16-19, leading us to re-examine our treatment algorithm and its results.
The aim of the present study was to examine the clinical and radiographic outcomes of anatomic shoulder arthroplasty for the treatment of type-1 fracture sequelae. Our hypothesis was that patients with type-1 fracture sequelae treated using anatomic unconstrained shoulder arthroplasty would have good and predictable functional results. Our primary goal was to define the prognostic factors and the limitations of hemiarthroplasty and total shoulder arthroplasty in this subgroup of patients.
Inclusion and Exclusion Criteria
The inclusion criteria were (1) implantation of an anatomic prosthesis (hemiarthroplasty or total shoulder arthroplasty) without tuberosity osteotomy for the treatment of cephalic collapse or necrosis (type-1 fracture sequelae), (2) use of a stemmed humeral implant of any type (standard, fracture, or short), (3) use of an all-polyethylene glenoid component in cases of total shoulder arthroplasty, and (4) a minimum of two years of follow-up. The exclusion criteria were (1) any other type of fracture sequelae (type 2, 3, or 4), (2) isolated nonunion or malunion of the greater or lesser tuberosity without cephalic collapse or osteonecrosis, (3) a preoperative shoulder infection, (4) a preoperative neurological deficit affecting the shoulder, (5) total shoulder arthroplasty with a metal-backed glenoid component, and (6) revision of a failed prosthesis implanted for an acute fracture.
Patient Population
Fifty-nine patients with type-1 fracture sequelae treated with anatomic shoulder arthroplasty fulfilled the inclusion criteria. Two patients died prior to two years postoperatively and two patients were lost to follow-up, leaving fifty-five patients (thirty-seven female and eighteen male) available for evaluation. Forty-four of these patients had undergone total shoulder arthroplasty, and eleven had undergone hemiarthroplasty. The mean age at the time of the shoulder arthroplasty was sixty-five years (range, forty to eighty-five years). The dominant side was affected in thirty-five patients (64%). Clinical and radiographic assessment of the fifty-five patients was performed by two different observers other than the surgeon at a mean of fifty-two months (range, twenty-four to 180 months) postoperatively.
Initial Fracture and Treatment
The initial proximal humeral fracture was classified retrospectively, according to the Neer system, on the basis of all available imaging studies20. Because patients presented from a variety of institutions, the initial radiographic evaluation was not standardized. There were nineteen minimally displaced (one-part) fractures, seven two-part fractures, two three-part fractures, twenty-two four-part fractures, and three four-part fracture-dislocations. Information was unavailable for the remaining two patients. Forty-four patients (80%) had undergone nonoperative treatment of the initial fracture, and eleven (20%) had undergone operative treatment. Of the latter, eight patients had undergone open reduction and internal fixation (including one patient in whom the fracture displaced after initial nonoperative treatment) and three had undergone percutaneous pinning. Thirty-seven patients had undergone no previous shoulder surgery before the shoulder arthroplasty, six had undergone one surgical procedure, and twelve had undergone two surgical procedures. The median time between injury and shoulder arthroplasty was seventy months (range, fourteen months to thirty-eight years).
Preoperative Radiographic Status
All patients had true anteroposterior and either axillary or lateral radiographs, and the presence of type-1 fracture sequelae was confirmed by consensus between three shoulder surgeons applying the principles of the previously described classification system13-15. Radiographs were standardized in accordance with our institution’s protocol and made with use of fluoroscopic guidance.
The extent of distortion of the proximal humeral anatomy varied among patients. Thus, the type-1 fracture sequelae were further subclassified according to the nature of the osseous deformation of the proximal aspect of the humerus, particularly the presence or absence of deformation of the greater tuberosity (Fig. 1). Eleven patients were considered to have type-1 fracture sequelae without proximal humeral deformity; six of these had isolated posttraumatic osteonecrosis of the humeral head without tuberosity malunion (type 1A), and five had isolated posttraumatic osteoarthritis without osteonecrosis or tuberosity malunion (type 1B). In contrast, forty-four patients had type-1 fracture sequelae with proximal humeral deformity; thirty had a valgus malunion secondary to a valgus impacted fracture (type 1C), and fourteen had a varus malunion secondary to a varus impacted fracture (type 1D). Valgus and varus malunion were defined according to the orientation of the greater tuberosity relative to the humeral diaphysis.
A preoperative computed tomography (CT) scan, CT arthrogram, or magnetic resonance imaging (MRI) scan was obtained in fifty-two patients to evaluate the extent of osteonecrosis, the status of the glenoid bone stock, and fatty infiltration of the rotator cuff muscles. Posttraumatic osteonecrosis of the humeral head was diagnosed in thirty-one patients (56% of the total cohort) and classified according to the Ficat21 system modified by Cruess22 for the shoulder; eight shoulders were stage 3, sixteen were stage 4, and seven were stage 5. Morphologic study of the glenoid in the fifty-two patients who underwent advanced imaging revealed forty-four type-A and eight type-B glenoids according to the Walch classification23. The global fatty degeneration index (GFDI) according to the Goutallier classification24 was <1 for eighteen patients, ≥1 in twenty-five, and not recorded for the twelve without a preoperative CT scan.
Operative Technique and Implants
The same senior shoulder surgeon (P.B.) performed the procedure in all patients. A deltopectoral approach was used. The subscapularis tendon and anterior capsule were divided at the medial edge of the lesser tuberosity in twenty patients, an osteotome was used to detach the tendon and capsule with bone chips from the lesser tuberosity in thirty patients, and a formal lesser tuberosity osteotomy was performed in five patients. The long head of the biceps was tenodesed in forty-six patients (84%). The supraspinatus tendon was partially torn or thin in ten patients, and it was repaired in one patient in which it was completely torn.
A third-generation anatomic, unconstrained, modular, and adaptable prosthesis25 was used (Aequalis shoulder prosthesis; Tornier, Edina, Minnesota). The goal of the surgeon was to adapt the humeral implant to the distorted anatomy of the proximal aspect of the humerus, which was accomplished by placing the prosthetic head at the level of the greater tuberosity or slightly higher. In all patients, the slight distortion of the proximal humeral anatomy was deemed acceptable and no greater tuberosity osteotomy was performed. Forty-four (80%) of the patients were treated with total shoulder arthroplasty and eleven (20%) with hemiarthroplasty. Depending on the degree of osseous distortion of the humerus, a standard stem was used in thirty-six patients (Fig. 2), a “low-profile” fracture stem was used in eleven (Fig. 3), and a short stem was used in eight (see Appendix). All stems were cemented, and a cemented keeled polyethylene implant was used to resurface the glenoid in all total shoulder arthroplasties. Intraoperative fluoroscopy was not utilized in any patient.
Postoperative Care
All shoulders were immobilized for four to six weeks postoperatively. Thirty-six shoulders were immobilized in a sling in internal rotation, sixteen were braced in neutral rotation, and three were braced in 30° of abduction. All patients began pendulum exercises immediately after surgery. Passive motion exercises and supervised physical therapy were initiated after four weeks. Active motion, strengthening, and stretching exercises were added progressively at the discretion of the operative surgeon.
Clinical and Radiographic Assessment
All preoperative and postoperative clinical assessments included (1) measurement of active shoulder anterior elevation, external rotation, and internal rotation with a goniometer; (2) evaluation of pain with a visual analog scale (VAS; range, 0 to 10); and (3) determination of the Constant score26. The normalized Constant score was also calculated as a percentage of the normal reference value adjusted for age and sex. Postoperative examinations were performed at six weeks, at six and twelve months, and annually thereafter. In order to obtain the longest follow-up possible, all patients were also asked to return to the clinic for the purposes of the study unless their follow-up was already scheduled during the period of data acquisition. The Subjective Shoulder Value (SSV)27 was obtained at this latest follow-up visit, and subjective results were evaluated with the question “Are you very satisfied, satisfied, disappointed, or dissatisfied with the result obtained with this procedure?” The measurements performed on postoperative anteroposterior radiographs are illustrated in the Appendix.
Statistical Analysis
The distribution of the data was analyzed with use of the D’Agostino-Pearson test. Preoperative and postoperative values of continuous variables were compared with use of the paired t test (for paired data) or the Mann-Whitney test (for unpaired data). The chi-square test and Fisher exact test for small numbers were used to compare categorical variables. A p value of 0.05 was considered significant.
Source of Funding
There was no external source of funding for this study. Tornier provided funding for travel to the conference at which the results of the study were presented.
Functional Results
Functional results were evaluated in all fifty-five patients (Table I). All measures of active motion and all parameters of the Constant score improved significantly. Pain values on the VAS improved significantly from 6.7 (range, 4 to 9) to 1.2 (range, 0 to 4) (p < 0.01).
Subjective and Radiographic Results
The mean SSV was 81% (range, 50% to 100%) at the time of the latest follow-up, and fifty-one patients (93%) were satisfied or very satisfied with the result. The results of the postoperative radiographic measurements are summarized in the Appendix.
Complications, Reoperations, and Revisions (Table II)
Three patients (5%) sustained an intraoperative humeral fracture. All fractures occurred in patients with proximal humeral deformity; two had varus malunion (type 1D) and one had valgus malunion (type 1C). Two of the patients sustained a greater tuberosity fracture at the time of humeral broaching; both fractures were fixed with use of heavy nonabsorbable sutures. One of these two patients also sustained a humeral shaft fracture, which was plated. In the third patient, a false track was created at the time of definitive humeral implantation, causing penetration of the humeral diaphyseal cortex.
Four postoperative complications occurred in four patients (7%). Two patients experienced temporary brachial plexus palsy, and both recovered fully within six months after surgery without additional surgical intervention. One patient underwent reoperation for biceps tendinitis and one for postoperative stiffness. There were no cases of postoperative infection.
Two patients (4%), both in the hemiarthroplasty cohort, experienced symptomatic glenoid erosion and underwent revision to total shoulder arthroplasty with implantation of an all-polyethylene glenoid component. In both cases, the humeral head was exchanged for a smaller component at the time of surgery, without revising the humeral stem, to maintain appropriate shoulder laxity.
Prognostic Factors
We identified two factors that significantly influenced clinical outcomes after shoulder arthroplasty for type-1 fracture sequelae. Patients without proximal humeral deformity had better results than patients with deformity, with significant differences in active elevation, the strength parameter of the Constant score, and the absolute Constant score (Table III and Fig. 4). Among the patients with proximal humeral deformity, those with valgus malunion had better results than those with varus malunion, with significant differences in active elevation, the absolute Constant score, and the range of motion and strength parameters of the Constant score (Table IV and Fig. 4). The status of the rotator cuff muscles, as evaluated on the CT scan, also affected the outcome. Patients with preoperative fatty infiltration of the rotator cuff muscles had poorer results than patients without fatty infiltration, with significant differences in active external rotation, the absolute Constant score, and the range of motion and activity parameters of the Constant score (Table V).
We also found that patients with a postoperative acromiohumeral distance of ≤7 mm had significantly poorer results than patients with a distance of >7 mm. With the numbers available, the treatment of the initial fracture, integrity of the rotator cuff tendons, position of the prosthetic head relative to the greater tuberosity, osteonecrosis of the humeral head, and delay between trauma and shoulder arthroplasty did not significantly influence the functional results (see Appendix).
Fracture of the proximal aspect of the humerus, with or without initial reduction and fixation, may lead to a spectrum of osseous deformity. In patients with type-1 fracture sequelae, the rotator cuff tends to be functional, so shoulder reconstruction with an anatomic, unconstrained shoulder prosthesis is a possible surgical option to treat severe functional impairment. The present study confirmed that the outcome of anatomic shoulder arthroplasty (hemiarthroplasty or total shoulder arthroplasty) to treat type-1 sequelae is good and predictable. The patients had significant improvement in shoulder function with respect to mobility, pain, and global function (Table I). These results are consistent with our previous findings13-15. Nevertheless, more severe proximal humeral deformity with greater tuberosity malunion was associated with inferior outcomes, as was fatty degeneration of the rotator cuff.
This study represents a homogeneous group of patients with a single type of fracture sequelae (type 1) and a single type of treatment (anatomic unconstrained shoulder arthroplasty). Our results are therefore difficult to compare directly with those of previous studies, which included heterogeneous patient populations, types of fracture sequelae, and types of treatment1,5,6,10-12,14,15,28-33. For example, Tauber et al.34 reported an average active anterior elevation of 120° and an active external rotation of 39° after shoulder arthroplasty for the treatment of posttraumatic osteonecrosis and collapse (type-1 sequelae) in thirty-eight patients. However, their treatments were heterogeneous, with the results of anatomic shoulder arthroplasty being combined with those of reverse shoulder arthroplasty.
Our attempt to identify the potential limitations of anatomic shoulder arthroplasty for the treatment of type-1 fracture sequelae led us to subclassify type-1 fracture sequelae, including differentiating between those with and without proximal humeral deformity (Fig. 1, Table VI). The results of anatomic shoulder arthroplasty were better in the absence of proximal humeral deformity, as the best outcomes occurred in cases of isolated necrosis of the humeral head (type 1A) and posttraumatic osteoarthritis (type 1B). Outcomes were also good and predictable in patients with valgus deformity (type 1C). In contrast, the outcomes in patients with varus malunion (type 1D) were significantly poorer than those in patients with valgus malunion (type 1C). Two hypotheses could explain this difference. It is technically more difficult to implant a humeral head prosthesis in a patient with substantial varus deformity because of the risk of greater tuberosity or diaphyseal fracture. In addition, the humeral medialization resulting from the varus deformity leads to circumferential tightening of the soft tissues and a severely stiff shoulder. The presence of fatty infiltration of the rotator cuff muscles was also associated with significantly poorer clinical outcomes. On the basis of the results of the present study, we consider patients with type-1 fracture sequelae with varus malunion and/or fatty infiltration of the rotator cuff muscles to be poor candidates for an anatomic prosthesis. In these situations, reverse shoulder arthroplasty may be preferable, especially if the patient is elderly.
Although the final functional results after anatomic arthroplasty for type-1 fracture sequelae are generally acceptable, one should be aware that this is a technically demanding procedure and that complications and reoperations should be anticipated. We have gradually improved and standardized our surgical technique in an attempt to avoid these complications. We have abandoned the technique of simple tenotomy of the subscapularis tendon, as this makes the subsequent release more difficult (the remaining musculotendinous unit is small and too medial) and the final repair is more fragile. Also, depending on whether or not a lesser tuberosity malunion is present, we now prefer to either perform a formal lesser tuberosity osteotomy or detach the tendon with some bone attached. This provides a bone-to-bone repair, which is thought to result in more reliable subscapularis function35. Since the management of the associated shoulder stiffness and soft-tissue contracture is essential to maximizing the outcome, we systematically perform anteroinferior capsulotomy, opening of the rotator interval, and biceps tenodesis in addition to the subscapularis release.
The good functional results seen in the present study may be related to some technical details. Our two main goals during reconstruction of the proximal aspect of the humerus are to restore the normal anatomy, by positioning the prosthetic head at or slightly above the level of the greater tuberosity, and to avoid performing a greater tuberosity osteotomy, as this has been shown to severely limit functional outcomes13-15. Utilization of a modular and adaptable prosthesis provides the flexibility to position the prosthetic head in a more anatomic position. We employ the variable prosthetic inclination (often preferring a 140° inclination) and humeral head eccentricity to compensate for the osseous deformity.
The importance of preoperative templating on both anteroposterior and axillary radiographs to optimize the humeral head and stem positioning cannot be overemphasized. Surgeons should be aware that the greater tuberosity is not upwardly migrated in type-1 fracture sequelae; rather, it is the humeral head that is downwardly impacted. Thus, the amount of humeral head that should be resected is often very small, and no humeral osteotomy may be required in cases of severe impaction of the head fragment. In such a case, the broaches should be introduced into the medullary canal by passing directly through the impacted humeral head fragment.
Templating also allows assessment of whether the distorted humeral anatomy will accommodate the insertion of a standard prosthetic humeral stem down the center of the medullary canal. We do not hesitate to use an undersized and/or short humeral stem, and we often prefer to use a “low-profile” fracture stem. These less bulky implants can help the surgeon to adapt the prosthetic head to the proximal humeral malunion and avoid impingement of the stem within the humeral shaft or against the greater tuberosity, which could lead to fracture. Use of a cemented humeral stem facilitates anatomic reconstruction in these cases. In contrast, uncemented press-fit prostheses fill the medullary canal with the biggest stem possible and reduce the surgeon’s ability to adapt to the distorted humeral anatomy. This can lead to poor positioning of the prosthetic head, thus overstuffing the joint and compromising the soft tissues.
The need for glenoid resurfacing in treating sequelae of proximal humeral fracture is debatable. In the present series, the glenoid was resurfaced in most patients. With the numbers available, the study lacked power to determine whether total shoulder arthroplasty yielded better results than hemiarthroplasty, but we feel that glenoid resurfacing plays an important role in restoring a pain-free and mobile shoulder. On the basis of the literature and our own experience, we pay close attention to the intraoperative appearance of the glenoid cartilage and have a low threshold for resurfacing.
There are some limitations to the current study. First, it is a retrospective study without a control group. Second, although the presence of type-1 fracture sequelae was established on the basis of a consensus of observers, the fact that all cases were drawn from a single surgeon’s practice potentially introduces selection bias regarding surgical treatment. Finally, although the available selection of prosthetic heads was identical throughout the study period, one could argue that the use of different humeral stems (standard, fracture, or short) may have affected the results. However, the choice of stem was guided by the extent of deformation of the proximal aspect of the humerus.
The present study also has several notable strengths. First, the group of fracture sequelae studied was very homogenous, and the cohort was large compared with those in other reports on this topic. Additionally, a high percentage of the patients were available for follow-up evaluation, with only two patients lost to follow-up over a lengthy study period.
In summary, the present study demonstrated that the functional outcomes obtained with anatomic shoulder arthroplasty to treat type-1 fracture sequelae were generally good and predictable. Nevertheless, patients with fatty infiltration of the rotator cuff muscles and patients with malunion of the greater tuberosity, especially those with varus malunion, had poorer results. In such cases, especially in elderly patients, reverse shoulder arthroplasty may be an appropriate alternative.
A table demonstrating which variables were not found to correlate with outcomes and figures showing a shoulder with type-1C sequelae and providing more information regarding preoperative and postoperative radiographic measurements are available with the online version of this article as a data supplement at jbjs.org.
Neer
CS
2nd;
Watson
KC;
Stanton
FJ. Recent experience in total shoulder replacement. J Bone Joint Surg Am.
1982 Mar;64(
3):319-37.
Neer
CS. Nonunion of the surgical neck of the humerus. Orthop Trans.
1983;3:389.
Antuña
SA;
Sperling
JW;
Sánchez-Sotelo
J;
Cofield
RH. Shoulder arthroplasty for proximal humeral malunions: long-term results. J Shoulder Elbow Surg.
2002 Mar-Apr;11(
2):122-9.[CrossRef]
Beredjiklian
PK;
Iannotti
JP;
Norris
TR;
Williams
GR. Operative treatment of malunion of a fracture of the proximal aspect of the humerus. J Bone Joint Surg Am.
1998 Oct;80(
10):1484-97.
Dines
DM;
Klarren
RF;
Altcheck
DW;
Moeckel
B. Posttraumatic changes of the proximal humerus: Malunion, nonunion, and osteonecrosis. Treatment with modular hemiarthroplasty or total shoulder arthroplasty. J. Shoulder Elbow Surg.
1993;2:11-21.[CrossRef][PubMed]
Norris
TR;
Turner
JA;
Bovill
D. .
Mansat
P;
Guity
MR;
Bellumore
Y;
Mansat
M. Shoulder arthroplasty for late sequelae of proximal humeral fractures. J Shoulder Elbow Surg.
2004 May-Jun;13(
3):305-12.[CrossRef]
Norris
TR;
Green
A;
McGuigan
FX. Late prosthetic shoulder arthroplasty for displaced proximal humerus fractures. J Shoulder Elbow Surg.
1995 Jul-Aug;4(
4):271-80.[CrossRef]
Tanner
MW;
Cofield
RH. Prosthetic arthroplasty for fractures and fracture-dislocations of the proximal humerus. Clin Orthop Relat Res.
1983 Oct;(
179):116-28.
Boileau
P;
Walch
G;
Trojani
C;
Sinnerton
R;
Romeo
AA;
Veneau
B. .
Boileau
P;
Trojani
C;
Walch
G;
Krishnan
SG;
Romeo
A;
Sinnerton
R. Shoulder arthroplasty for the treatment of the sequelae of fractures of the proximal humerus. J Shoulder Elbow Surg.
2001 Jul-Aug;10(
4):299-308.[CrossRef]
Boileau
P;
Chuinard
C;
Le Huec
JC;
Walch
G;
Trojani
C. Proximal humerus fracture sequelae: impact of a new radiographic classification on arthroplasty. Clin Orthop Relat Res.
2006 Jan;442:121-30.[CrossRef]
Raiss
P;
Kasten
P;
Baumann
F;
Moser
M;
Rickert
M;
Loew
M. Treatment of osteonecrosis of the humeral head with cementless surface replacement arthroplasty. J Bone Joint Surg Am.
2009 Feb;91(
2):340-9.[CrossRef]
Boileau
P;
Watkinson
D;
Hatzidakis
AM;
Hovorka
I. Neer Award 2005: The Grammont reverse shoulder prosthesis: results in cuff tear arthritis, fracture sequelae, and revision arthroplasty. J Shoulder Elbow Surg.
2006 Sep-Oct;15(
5):527-40.[CrossRef]
Neyton
L;
Garaud
P;
Boileau
P. .
Neer
CS
2nd. Displaced proximal humeral fractures. I. Classification and evaluation. J Bone Joint Surg Am.
1970 Sep;52(
6):1077-89.
Ficat
RP. Idiopathic bone necrosis of the femoral head. Early diagnosis and treatment. J Bone Joint Surg Br.
1985 Jan;67(
1):3-9.
Cruess
RL. Corticosteroid-induced osteonecrosis of the humeral head. Orthop Clin North Am.
1985 Oct;16(
4):789-96.
Walch
G;
Badet
R;
Boulahia
A;
Khoury
A. Morphologic study of the glenoid in primary glenohumeral osteoarthritis. J Arthroplasty.
1999 Sep;14(
6):756-60.[CrossRef]
Goutallier
D;
Postel
JM;
Gleyze
P;
Leguilloux
P;
Van Driessche
S. Influence of cuff muscle fatty degeneration on anatomic and functional outcomes after simple suture of full-thickness tears. J Shoulder Elbow Surg.
2003 Nov-Dec;12(
6):550-4.[CrossRef]
Boileau
P;
Walch
G. The three-dimensional geometry of the proximal humerus. Implications for surgical technique and prosthetic design. J Bone Joint Surg Br.
1997 Sep;79(
5):857-65.[CrossRef]
Constant
CR;
Murley
AH. A clinical method of functional assessment of the shoulder. Clin Orthop Relat Res.
1987 Jan;(
214):160-4.
Gilbart
MK;
Gerber
C. Comparison of the subjective shoulder value and the Constant score. J Shoulder Elbow Surg.
2007 Nov-Dec;16(
6):717-21.[CrossRef]
Huten
D;
Duparc
J. [Prosthetic arthroplasty in recent and old complex injuries of the shoulder]. Rev Chir Orthop Reparatrice Appar Mot.
1986;72(
8):517-29. .[PubMed]
Frich
LH;
Søjbjerg
JO;
Sneppen
O. Shoulder arthroplasty in complex acute and chronic proximal humeral fractures. Orthopedics.
1991 Sep;14(
9):949-54.
Habermeyer
P;
Schweiberer
L. [Corrective interventions subsequent to humeral head fractures]. Orthopade.
1992 Apr;21(
2):148-57. .
Postel
JM;
Tamames
M;
Lenoble
E;
Goutallier
D. Les arthroses post-traumatiques. Rev Chir Orthop Reparatrice Appar Mot.
1995;81(
Suppl II):111-5.
Bosch
U;
Skutek
M;
Fremerey
RW;
Tscherne
H. Outcome after primary and secondary hemiarthroplasty in elderly patients with fractures of the proximal humerus. J Shoulder Elbow Surg.
1998 Sep-Oct;7(
5):479-84.[CrossRef]
Duparc
F;
Trojani
C;
Boileau
P. .
Tauber
M;
Karpik
S;
Matis
N;
Schwartz
M;
Resch
H. Shoulder arthroplasty for traumatic avascular necrosis: predictors of outcome. Clin Orthop Relat Res.
2007 Dec;465:208-14.
Jandhyala
S;
Unnithan
A;
Hughes
S;
Hong
T. Subscapularis tenotomy versus lesser tuberosity osteotomy during total shoulder replacement: a comparison of patient outcomes. J Shoulder Elbow Surg.
2011 Oct;20(
7):1102-7. .[CrossRef]
Disclosure: One or more of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of an aspect of this work. In addition, one or more of the authors, or his or her institution, has had a financial relationship, in the thirty-six months prior to submission of this work, with an entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. No author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.