The patient is placed in the prone position on the operating table. We
recommend using the Wilson spine table, which flexes the patient at the hips
(Figs. 1-A and 1-B). This
position helps with retraction of the gluteus maximus superiorly and therefore
improves exposure of the ischium. It is helpful for the surgeon to have a head
lamp to improve visualization of the ischial tuberosity, especially when
operating on larger patients.
We approach the repair of the proximal origin of the hamstrings through a
transverse incision made in the gluteal
crease7. The
incision is cosmetic and in most cases allows ample access to the avulsed
tendons. If necessary, the incision can be extended longitudinally for greater
exposure, which may be necessary in chronic cases. This is accomplished by
performing a longitudinal limb incision extending from the center of the
transverse incision (Fig. 2).
The skin incision is carried down through the subcutaneous tissues to the
gluteal fascia. A transverse incision is then made in the gluteal fascia to
expose the inferior border of the gluteus maximus muscle. The gluteus maximus
is retracted superiorly to gain access to the fascia overlying the hamstrings
as well as the ischium. A longitudinal incision is then made in the hamstring
fascia. In acute cases, a large hematoma or fluid collection is typically
encountered and evacuated. The hamstring tendons are then identified
(Fig. 3). In order to expose
the ischium, the inferior border of the gluteus maximus muscle needs to be
mobilized and retracted superiorly after the posterior fascia of the hamstring
compartment has been divided. In a previous
study14, we
determined that the average distance from the superior border of the ischium
to the inferior border of the gluteus maximus is 6.3 ± 1.3 cm and that,
at the lateral border of the ischium, the distance from the inferior gluteal
nerve and artery to the inferior border of the gluteus maximus is 5.0 ±
0.8 cm (Fig. 4). With a
retractor placed underneath the gluteus maximus, it is possible to
inadvertently cause a traction injury to the nerve or its associated vessel.
Therefore, we suggest using gentle retraction with a retractor blade depth of
no more than 4 cm when exposing the ischium.
In all surgical cases, we recommend identifying the sciatic nerve to avoid
injury. In our previous study, we found that the sciatic nerve lies 1.2
± 0.2 cm lateral to the most lateral aspect of the ischial tuberosity.
In patients who have a chronic injury, the sciatic nerve often can be scarred
into the hamstring tendons. In that case, we recommend that the nerve first be
identified more distally where it appears to be normal and that the dissection
then proceed proximally.
Once the hamstring tendons are found, the ends are débrided and
freshened; care should be taken to avoid excessive shortening, which may
prevent reattachment. The ischial tuberosity is then exposed by removing any
residual soft tissue with cautery, and the bone is freshened with use of a
curette or periosteal elevator. In our anatomic study, the semitendinosus and
biceps femoris tendons were found to have a common site of origin on the
ischium, lying medial to the origin of the semimembranosus. This is where the
corkscrew suture anchors are placed for fixation. The semitendinosus/biceps
femoris origin was found to be oval in shape, with average measurements of 2.7
± 0.5 cm from proximal to distal and 1.8 ± 0.2 cm from medial to
lateral. The semimembranosus origin is also vertically oriented and adjacent
to that of the semitendinosus but is crescentic in shape, measuring 3.1
± 0.3 cm from proximal to distal and 1.1 ± 0.5 cm from medial to
lateral (Fig. 5). When there is
a complete avulsion, we have found that it is best to restore these anatomic
relationships by placing an anchor more laterally for the semimembranosus
tendon because it crosses beneath the common semitendinosus/biceps femoris
tendon.
We recommend using double-loaded metal corkscrew anchors with nonabsorbable
suture material for fixation. Typically, one anchor is adequate for the
semimembranosus and one or two anchors are employed for the
semitendinosus/biceps femoris tendon. The anchor is first placed in the
ischial tuberosity. One end of the suture is used to place a running locking
stitch from proximal to distal and then from distal to proximal in the tendon.
This is then repeated for one of the arms of the second suture. The opposite
ends of each suture are then used to pull the tendon to the ischium and are
tied together with the knee flexed to 30°
(Figs. 6-A, 6-B, and 6-C). The
wound is then copiously irrigated, and the fascia is closed. The subcutaneous
tissues are reapproximated, and the skin is closed with a running subcuticular
stitch. We recommend sealing the skin with Dermabond (Ethicon, Somerville, New
Jersey).
Postoperatively, the patient is placed in a custom hinged brace that
prevents hip flexion. The patient walks with crutches and foot-flat touch-down
weight-bearing for two weeks. After two weeks, partial weight-bearing to 25%
is permitted. Weight-bearing is increased weekly with a goal of full
weight-bearing by six weeks. Starting at two weeks, gentle passive range of
motion of the hip and knee is permitted. At six weeks, the brace is
discontinued, full weight-bearing is allowed, and active range of motion is
initiated. Passive stretching is continued to restore full range of motion and
to further improve hamstring flexibility. In addition, a closed-chain exercise
program and core strengthening should be implemented. At three months, aerobic
conditioning begins. We recommend beginning a non-impact activity such as the
use of an elliptical trainer or StairMaster followed by a light jogging
program. An isokinetic evaluation should be performed to ensure that the
injured extremity has regained at least 80% of the strength of the uninjured
limb before return to sports. Typically, one can expect to return to sports at
approximately six months.
CRITICAL CONCEPTSINDICATIONS:The principal indications for primary repair of proximal hamstring injuries
include a complete avulsion of all three tendons (i.e., semitendinosus,
semimembranosus, and biceps femoris). This injury is suspected when an
appropriate mechanism is associated with a palpable or audible
"snap" or "pop" in the buttocks as described by the
patient. This is usually associated with considerable ecchymosis in the
posterior aspect of the thigh and can result in a palpable defect in the
proximal hamstring tendon. When the injury is suspected, magnetic resonance
imaging of the hip is used to evaluate the proximal hamstring tendons.
Retraction is usually seen on magnetic resonance imaging in association with a
three-tendon injury. It has been reported that retraction of =2 cm of two
tendons is associated with an injury of the third tendon, and this scenario in
young (less than fifty-year-old), active individuals is a relative indication
for surgical
treatment15.CONTRAINDICATIONS:Contraindications include injury to a single tendon, regardless of the
amount of retraction, or multiple tendons with minimal retraction (<2 cm).
Repair is not indicated for elderly or sedentary patients.PITFALLS:Pitfalls include neurovascular injuries. Specific structures at risk
include the sciatic nerve and the inferior gluteal nerve and artery. The
sciatic nerve is more at risk of operative injury in the setting of a chronic
avulsion in which the tendons have scarred into the nerve. The inferior
gluteal nerve and vessels are at risk of traction injury with aggressive
retraction of the gluteus maximus as described above.AUTHOR UPDATE:No changes to the procedure have been made since the initial
publication.
CRITICAL CONCEPTS
INDICATIONS:
The principal indications for primary repair of proximal hamstring injuries
include a complete avulsion of all three tendons (i.e., semitendinosus,
semimembranosus, and biceps femoris). This injury is suspected when an
appropriate mechanism is associated with a palpable or audible
"snap" or "pop" in the buttocks as described by the
patient. This is usually associated with considerable ecchymosis in the
posterior aspect of the thigh and can result in a palpable defect in the
proximal hamstring tendon. When the injury is suspected, magnetic resonance
imaging of the hip is used to evaluate the proximal hamstring tendons.
Retraction is usually seen on magnetic resonance imaging in association with a
three-tendon injury. It has been reported that retraction of =2 cm of two
tendons is associated with an injury of the third tendon, and this scenario in
young (less than fifty-year-old), active individuals is a relative indication
for surgical
treatment15.
CONTRAINDICATIONS:
Contraindications include injury to a single tendon, regardless of the
amount of retraction, or multiple tendons with minimal retraction (<2 cm).
Repair is not indicated for elderly or sedentary patients.
PITFALLS:
Pitfalls include neurovascular injuries. Specific structures at risk
include the sciatic nerve and the inferior gluteal nerve and artery. The
sciatic nerve is more at risk of operative injury in the setting of a chronic
avulsion in which the tendons have scarred into the nerve. The inferior
gluteal nerve and vessels are at risk of traction injury with aggressive
retraction of the gluteus maximus as described above.
AUTHOR UPDATE:
No changes to the procedure have been made since the initial
publication.