Orthopaedic rehabilitation involves the care of patients who have complex musculoskeletal problems, which are global in nature rather than being limited to one or two anatomic locations. It is a specialty that combines biomechanics and biology in a unique manner with an approach that focuses on improving the functional outcome for individuals with musculoskeletal disability through surgical and nonsurgical management.
This specialty encompasses patients of all ages, a broad range of anatomic locations, and a variety of musculoskeletal dysfunctions. Orthopaedic rehabilitation comprises all of the traditional orthopaedic subspecialties, including amputation surgery, prosthetic and orthotic management, neuromuscular diseases, and a variety of other neurologic disorders, with a focus on the musculoskeletal system as a whole as well as on the linkages and couplings between bones, joints, muscles, and the nervous system.
This update highlights presentations and advances in several areas of orthopaedic rehabilitation that were discussed at meetings of the Orthopaedic Rehabilitation Association, the American Academy of Orthopaedic Surgeons, and other specialty organizations over the past year. The review also highlights the papers that received the Jacquelin Perry Award and the Vernon Nickel Award, the two prestigious awards in orthopaedic rehabilitation that are presented annually by the Orthopaedic Rehabilitation Association.
Motion analysis and dynamic electromyography are important tools in the analysis of movement and lower extremity function. These modalities can be utilized by the surgeon to create both operative and nonoperative treatment protocols.
There have been several developments in the use of treadmills for gait analysis. Riley et al.1 examined the differences between overground and treadmill running in terms of kinematics and kinetics. With the advent of instrumented treadmills that permit the measurement of ground-reaction force, the instrumented treadmill has become an important tool that can be used by the clinician for high-velocity gait analysis. The authors examined twenty healthy, young joggers who ran at least fifteen miles (24.1 km) per week. Subjects ran on both instrumented treadmills and on an overground 15-m runway at their 10-km-race pace. Instrumented treadmill running led to a higher cadence (p = 0.0086), shorter stride length (p = 0.0001), shorter stride time (p = 0.0011), decreased maximum knee flexion (p = 0.005), increased minimum knee flexion (p = 0.006), and decreased ground-reaction forces (p < 0.02). In addition, differences between the two forms of running were identified for joint moment and joint power trajectories. The authors concluded that parameters measured with an adequate, instrumented treadmill are comparable with but not directly equivalent to those of overground running. Yet, the instrumented treadmill is still an important clinical tool that can be utilized for high-velocity gait analysis if the differences between overground and treadmill running are recognized. The authors extrapolated that with a stiffer treadmill surface and better regulation of belt speed, the differences between treadmill and overground running analysis can be bridged.
Stoquart et al.2 further examined treadmills by analyzing the effect of speed on kinematic, kinetic, electromyographic, and energetic reference values during treadmill walking (as opposed to running). Whereas kinematic, kinetic, and electromyographic data are classically obtained during overground walking, energetic data are obtained on treadmills. The limitation of overground testing is that it is very often done at self-selected speeds, whereas the treadmill allows control of speed. The purpose of that study was to assess the feasibility of extended gait analysis on a treadmill, allowing multiple steps to be recorded at a constant speed for young healthy subjects. In addition, the authors attempted to develop speed-specific kinematic, kinetic, electromyographic, and energetic reference values that could be utilized in future studies. Twenty young volunteers walked on a force-measuring treadmill at six speeds ranging from 1 to 6 km/hr. Hip, knee, and ankle kinematics and kinetics were analyzed, as were electromyographic muscle activity and energy cost (on the basis of oxygen-consumption measurements). The authors found that all variables were speed-dependent. With increased walking speed, kinematics and kinetic peak amplitude increased and occurred earlier during the walking cycle. Furthermore, muscle activity timing changed with speed, and energy cost produced a U-shaped curve (with minimum values at 4 km/hr). The authors concluded that their data provide kinematic, kinetic, and electromyographic reference data for healthy subjects based on the speed of the subject while walking on the treadmill, allowing for extrapolation to other studies based on subject speed.
Sturnieks et al.3 provided a connection between gait analysis and clinical sports medicine by examining knee strength and knee adduction moments following arthroscopic partial medial meniscectomy. One hundred and two patients who had undergone meniscectomy were compared with forty-two age-matched controls who had not had an operation. The patients and controls underwent strength testing (with use of isometric, isokinetic, and concentric knee strength measurements) as well as three-dimensional gait analysis at each subject's self-selected walking speed. Hip, knee, and ankle kinetic and kinematic data were collected. From the strength-testing data, patients were also divided into weak and normal subgroups. The authors found that the arthroscopic partial medial meniscectomy group had weaker concentric knee extension and flexion strength (p < 0.001 and p = 0.033, respectively). Furthermore, the weak meniscectomy subgroup had increased average (p < 0.033) and peak knee adduction moments (p < 0.032) during stance when compared with both the normal-strength meniscectomy subgroup and the controls. In addition, the normal strength meniscectomy subgroup had a larger peak knee adduction moment in early and late stance (p = 0.005) as compared with the controls. The authors concluded that, in order to resume normal frontal plane loading of the knee during walking, the achievement of normal muscle strength is paramount.
Continuing with the use of gait analysis to evaluate clinical conditions, Lai et al.4 performed three-dimensional gait analysis of obese patients in order to better characterize the role of obesity in walking. Fourteen obese subjects (average body mass index, 33.06) were compared with fourteen non-obese subjects (average body mass index, 21.33) in terms of kinematic and kinetic data that were obtained with use of a self-selected walking speed and a three-dimensional motion-analysis system. The authors found that obese patients spent more time during stance (p < 0.05) and double support (p < 0.01) and had a lower self-selected walking speed (p < 0.01), shorter stride length (p < 0.01), greater hip adduction during terminal stance (p < 0.01) and pre-swing (p < 0.05), greater knee adduction angles (p < 0.05), increased ankle eversion angles (p < 0.05), increased ankle inversion moments (p < 0.05), and reduced peak ankle plantar flexor moments (p < 0.01). The authors concluded that the differences in the three-dimensional gait analysis between the obese and non-obese subjects were adaptations of the obese patients to their heavy body weight, particularly attempts by the obese patients to reduce moments about the knee and energy expenditure.
Interest in amputation surgery and prosthetics has been in the international spotlight with controversy regarding South African double amputee sprinter Oscar Pistorius's ambitions to compete in the able-bodied Olympics and the purported advantage (or disadvantage) that his prosthetic limbs confer to him. This dialogue has raised awareness of the tremendous technological advances that are now available to individuals who have undergone amputation surgery, allowing patients to return to a high level of function. This has been of particular importance to the large numbers of young soldiers who have experienced traumatic amputations in conflicts across the globe.
Hagberg et al.5 performed the first prospectively designed outcomes study on tumor and trauma patients with transfemoral osseointegrated (i.e., bone anchored) prostheses. The main purpose of their study was to analyze general and condition-specific health-related quality-of-life changes in eighteen consecutive patients prior to, and two years after, treatment with an osseointegrated prosthesis. The Short Form-36 (SF-36) health survey and the Questionnaire for Persons with a Transfemoral Amputation (Q-TFA) were administered preoperatively and postoperatively. The authors found that there was a significant improvement in the physical functioning, role functioning physical, bodily pain, and physical component subscores of the SF-36 as well as the prosthetic use, prosthetic mobility, problems, and general health scores of the Q-TFA at the time of follow-up (after placement of an osseointegrated prosthesis) as compared with the preoperative status. These improvements in SF-36 and Q-TFA scores were extrapolated to superior quality of life, increased prosthetic use, better prosthetic mobility, decreased problems, and a better overall amputation condition. The authors concluded that osseointegrated prostheses are a promising development for individuals with transfemoral amputations that can lead to an improved quality of life at the time of the two-year follow-up.
Whereas the previous study examined the use of a specific prosthesis for transfemoral amputations, Baum et al.6 retrospectively examined the effect of residual limb length on gait parameters in patients with transfemoral and knee-disarticulation amputations. As prostheses evolve, there is a lack of objective data on the correct level for transfemoral amputations as it relates to gait as well as on the relationship between gait and knee disarticulation. The purpose of that study was to determine how temporal-spatial, kinematic, and kinetic trends correlate with the length of the residual femur in patients with transfemoral and knee-disarticulation amputations. The authors retrospectively reviewed gait analysis data on thirteen active, young soldiers (mean age [and standard deviation], 30.7 ± 6.7 years) who underwent a unilateral transfemoral or knee-disarticulation amputation following a traumatic injury. To prevent variability based on the prosthesis, all individuals used the C-Leg microprocessor knee unit (Otto Bock, Duderstadt, Germany) in conjunction with their everyday foot, which in each case was an all multiaxial, energy storage and return (ESAR) foot. Residual limb lengths were measured from the greater trochanter to the distal aspect of the limb. Among the thirteen patients in the study, the residual limb ratio, as compared with the contralateral, intact limb, ranged from 57% (transfemoral level) to 100% (knee disarticulation). The authors found that after the removal of one outlier, pelvic tilt excursion was inversely related to residual limb length (R2 = 0.465). Otherwise, the authors found no correlation between residual limb ratio and velocity, cadence, step length or stance time of the prosthetic limb, step length or stance time of the intact limb, step width, hip flexion, trunk lateral flexion, and trunk forward lean. The authors concluded that if the length of the amputated femur is at least 57% of that of the contralateral femur, dramatic changes in gait are not expected. The authors noted that "This implies that surgeons may have more flexibility to amputate at a higher level to preserve soft tissue quality and improve prosthetic fitting without sacrificing gait function."
One of the critical tasks that the clinician faces after successful amputation is the long-term management of the patient's prosthesis. As a result, one of the important roles of the physician is to prescribe the proper prosthesis so that the patient's gait and function are not impaired. The ability to accurately determine the patient's activity level is essential in this process and was examined by Stepien et al.7. The purpose of that study was to compare the number of steps that lower-limb amputees take per day and to compare their self-reported step number (by means of an activity diary) with that recorded with the StepWatch Activity Monitor (SAM) 3.0 (Cyma, Mountlake Terrace, Washington), which has been shown to be 99.7% accurate for determining activity levels in lower-limb amputees8. Seventy-seven patients with a unilateral lower-limb amputation who had undergone at least six months of prosthetic rehabilitation were studied. Activity counts (steps/min) and self-reported activity level (rest, low, medium, high) were recorded for fifteen-minute time intervals over a total period of one week for each participant with use of both the patient's diary and the SAM (which was fitted to the patient's prosthesis and continuously recorded activity). The authors found that the participants' self-reported and measured activity strongly agreed (gamma = 0.7) for only 34% of the participants during waking hours. The self-reported and measured activity levels also showed poor agreement for each state of activity (rest [r = 0.41], low level [r = 0.39], medium level [r = 0.26], high level [r = 0.40]). The authors did find that the transtibial amputees took more steps per day on the average than the transfemoral amputees did and that there was no bias toward over-reporting or under-reporting of the level of activity among all amputees. The authors concluded that the use of self-reported activity levels may have consequences for both patients and funding agencies (such as insurance companies) as these measurements are not accurate. Under-reporting of activity can prevent patients from being prescribed the prosthesis that will most effectively meet their activity level and walking ability. Over-reporting of activity can lead patients and funding agencies to pay for advanced prostheses that are unnecessary for patients with low activity levels.
In line with the work by Stepien et al.7 with regard to the utilization of the proper prosthetic design for patients, Adderson et al.9 examined the effect of a shock-absorbing pylon on the peak magnitude and frequency content of the heel-strike-initiated shock wave transmitted to the residual limb as well as the relationship between heel-strike transient force and function. The authors examined seven patients with unilateral transtibial amputation who walked at self-selected speeds with and without the shock-absorbing pylon. Accelerometers (mounted along the prosthetic pylon) were used to measure transmitted shock waves, force plates were used to measure ground-reaction forces, ten-minute walking tests were used to determine walking speed, and questionnaires were used to evaluate gait function and subjective preference for the shock-absorbing pylon. The authors found that the shock-absorbing pylon provided no significant shock absorption (p = 0.28) or change in frequency content. Furthermore, there were no significant differences in terms of ground-reaction force, walking speed, gait function, or subjective preference. The authors concluded that there is no evidence to suggest a significant effect of the shock-absorbing pylon, although additional study is necessary because of the high variance in the study.
Each year the Orthopaedic Rehabilitation Association holds a competition for the best original research paper by a resident or fellow. These awards are named in honor of the two pioneers in this field, Dr. Jacquelin Perry and Dr. Vernon Nickel. The Perry Award paper is presented at the Orthopaedic Rehabilitation Association Specialty Day Program held in conjunction with the annual meeting of the American Academy of Orthopaedic Surgeons. The Nickel Award paper is presented at the annual meeting of the Orthopaedic Rehabilitation Association.
The Jacquelin Perry Award Paper 2008: Orthopaedic Management Improves the Early Rate of Osteoporosis Treatment after Hip Fracture
Miki et al.49 compared the effect of osteoporosis management initiated by the orthopaedic team with the effect of osteoporosis management performed by the primary care physician on the rates of treatment at six months. A prospective randomized trial was conducted to assess the difference in the rate of osteoporosis treatment when an in-house assessment of osteoporosis was initiated by the orthopaedic surgeon and follow-up was conducted in a specialized orthopaedic osteoporosis clinic as compared with osteoporosis education and "usual" care. Sixty-two patients were enrolled in the study and were randomized, by means of sealed envelopes, to either the study group or the control group. The percentage of patients who were receiving pharmacological treatment for osteoporosis at six months after the fracture was significantly greater when the evaluation was initiated by the orthopaedic surgeon and the patient was managed in a specialized orthopaedic osteoporosis clinic than it was when the patient was managed by the primary care physician (58% compared with 29%; p = 0.04).
The percentage of patients who started treatment and the number of patients who had a bone mineral density scan within six months after the hip fracture were also significantly greater in the study group (p = 0.002 and p < 0.0001, respectively). The trial was stopped before the pretrial estimate of 120 patients was reached because intermediate-term analysis demonstrated a significant difference in the rate of treatment between the two groups. A post hoc power analysis demonstrated a power of 0.61.
The Vernon Nickel Award Paper 2008: The Effect of Sitting Pressure on Ischial Blood Flow in Spinal Cord Injured Patients vs. Non-Injured Controls
Noiseux50 performed a physiologic study in which incremental pressures that were applied at the ischial tuberosities were compared with alterations in the local cutaneous perfusion in this area. Patients with spinal cord injuries were compared with uninjured controls in order to detect any significant differences in the pressure-perfusion relationship between them. Subjects were progressively lowered, with use of a patient lift, onto a seat where perfusion was measured with laser Doppler perfusion imaging and pressure was recorded with a pressure mapping system. The mean pressure-perfusion curve was determined from a zero-loaded position to a maximally loaded position.
Healthy controls exhibited stable cutaneous ischial tissue perfusion in association with sitting pressures of up to 150 mm Hg, followed by a 10% increase in blood flow at higher peak pressures. In contrast, subjects with spinal cord injuries underwent an early decrease in perfusion of 20% in association with pressures of up to 150 mm Hg, with a subsequent leveling off of blood flow at higher pressures. The patients with spinal cord injuries also demonstrated lower reperfusion values, indicative of a weaker reactive hyperemia, in response to pressure.
Noiseux concluded that, compared with uninjured controls, patients with spinal cord injuries appeared to have inherent blood flow regulation differences in response to pressure in the subischial tissues, possibly because of a dysfunction in an autonomic phenomenon termed pressure-induced vasodilation. However, a threshold pressure for maintaining optimal perfusion remains elusive for both healthy subjects and patients with spinal injuries. Future steps should be directed at targeting the altered blood flow response to pressure in patients with spinal cord injuries, pharmacologically or mechanically, which may lead to a reduction in the prevalence of decubital ulcers.