Mark H. Gonzalez

Bone transport in the management of posttraumatic bone defects in the lower extremity.

BACKGROUND The aim of this study was to evaluate the clinical and functional outcomes of traumatic bone defects of the lower extremity managed by internal bone transport using the Ilizarov technique. METHODS We retrospectively reviewed 19 patients who underwent internal bone transport for traumatic bone defects in the lower extremity. Mean follow-up was 68.7 months (5.7 years). Eighteen cases were open: grade IIIA, 10 cases; grade IIIB, 4 cases; and grade IIIC, 4 cases. RESULTS Clinical outcome was 2 excellent, 11 good, 4 fair, and 2 poor. Eighteen of 19 patients reported being satisfied. The results of the SF-36 Health Survey showed a significant difference between the population norm and the mean of the study group in Physical Functioning, Bodily Pain, and Role-Emotional. The mean length of time in external fixation for all patients was 13.8 months. The mean length of regenerate was 5.7 cm (range, 0.8-20.4 cm). The total number of complications was 39 (20 minor and 19 major). Major complications included two transtibial amputations and four fractures at the docking site. CONCLUSION Although the number of complications was high, the patients in this study were satisfied to have their limbs preserved. The SF-36 Health Survey showed that patients suffer mainly from physical and emotional consequences after these major injuries. Their general, social, and mental health is usually not affected. Infection significantly increased the healing index. The limb should be protected for a long time, with careful evaluation to avoid fracture at the docking site after fixator removal.

The first dorsal extensor compartment: An anatomic study*

Sixty-six cadaver hands were dissected to better define the anatomic variations of the first dorsal compartment and the superficial radial nerve. A septum was present in 31. A separate compartment enclosed the extensor pollicis brevis tendon in 29 and a slip of the abductor pollicis longus in 2. Multiple slips of the abductor pollicis longus tendon were noted in 38. Accessory slips inserted into the trapezium and thenar musculature. Partial separation or grooving of the abductor pollicis longus tendon was common but did not necessarily define a separate tendon slip.

Flexible intramedullary nailing for metacarpal fractures

A 5-year retrospective review of 83 patients with 98 metacarpal fractures was performed. Fractures of the thumb metacarpal were excluded. Ninety-six closed metacarpal fractures were reduced closed and fixed with flexible intramedullary fixation, using multiple 0.8-mm prebent rods. Two open metacarpal fractures were also fixed with this technique. Fractures amenable to flexible intramedullary fixation include short oblique and transverse fractures. Contraindications include long oblique and bicortical comminuted fractures. The average follow-up time was 9 months (range, 2 to 34 months) with 15 patients lost to follow-up examination. All fractures went on to heal. Three complications occurred: backing out of a rod in one case and bending of the rods after repeat trauma in two. There were no infections. Flexible intramedullary nailing of specific metacarpal fractures affords excellent results with a low complication rate. Proper selection of fractures and good surgical technique are necessary to avoid complications.

Proprioception after arthroplasty: role of the posterior cruciate ligament.

To test the hypothesis that retaining the posterior cruciate ligament during total knee arthroplasty helps preserve the threshold of proprioceptive sensation, a machine was designed that permitted direct measurement of passive angular deflection from a resting point to the threshold of patient perception. Sixty patients with unilateral primary total knee arthroplasties were evaluated; 30 with posterior cruciate ligament retaining prostheses and 30 with posterior cruciate ligament substituting prostheses. All patients had a minimum postoperative followup of 1 year, a good or excellent result as defined by the Hospital for Special Surgery Knee Score, and no evidence of peripheral neuropathy. The gender and age distributions were equivalent between groups. The average threshold of perception for the posterior cruciate ligament retention group was 2.4 °. The average threshold of perception for the posterior cruciate ligament substitution group was also 2.4 °. Substitution or retention of the posterior cruciate ligament makes no clinical difference in proprioception as measured by threshold testing. This study provides new information for surgeons performing total knee arthroplasty to aid in the decision to retain or substitute the posterior cruciate ligament. Previous proprioception evaluation in patients with posterior cruciate ligament retaining versus posterior cruciate ligament substituting arthroplasties, using different testing methods, has revealed different results.

Free tissue coverage of chronic traumatic wounds of the lower leg.

&NA; Thirty‐eight consecutive patients who underwent 42 free flaps for chronic wounds of the lower leg were identified over an 11‐year period. All wounds were open for a minimum of 1 month (mean, 40 months; median, 8 months; range, 1 month to 30 years). The average age was 37 years (range, 7 to 68 years), there were 31 male patients and seven female patients, and the average follow‐up time was 30 months (range, 12 to 72 months). The original injury was an open fracture in 28 patients, wound dehiscence after open reduction and internal fixation of a closed fracture in nine patients, and a shrapnel wound in one patient. A total of 23 patients had osteomyelitis, which was classified as local (involving less than 50 percent of the bone diameter) in 15 patients and as diffuse (involving greater than 50 percent of the bone diameter or infected nonunion) in eight patients. The wounds were treated with sequential debridement, antibiotics, and flap coverage. Ancillary procedures included antibiotic beads in 18 patients, saucerization in 16, Ilizarov bone transport in three, calcanectomy in two, and fibular resection and ankle fusion in one. Thirty‐four of 42 flaps survived, four having undergone a repeat free flap. There were three failures out of 25 flaps (12 percent) among those with a normal angiogram and five failures out of 15 flaps (33 percent) among those with an abnormal angiogram (p > 0.05). The failure rate of those with osteomyelitis was six of 26 (23 percent) versus two of 26 (13 percent) for those without osteomyelitis (p > 0.05). Successful reconstruction (bone healed, patient ambulatory and infection‐free) was achieved in 33 of 38 patients (87 percent). The failure of reconstruction for those patients with osteomyelitis was four of 23 (22 percent) versus one of 15 (7 percent) for others (p > 0.05). The failure rate of flaps in patients with diffuse osteomyelitis was three of eight (38 percent) versus two of 30 for others (7 percent, p = 0.053). The presence of diffuse osteomyelitis was associated with a lower rate of successful limb reconstruction. An abnormal angiogram and the presence of osteomyelitis both were associated with a lower rate of successful limb reconstruction, but this was not significant, probably because of the small size of the cohort. (Plast. Reconstr. Surg. 109: 592, 2002.)

The Ulnar Nerve at the Elbow and its Local Branching: An Anatomic Study

Thirty nine cadaver elbows were dissected and the branching of the ulnar nerve, as well as the cubital tunnel and adjacent potential sites of nerve compression were studied. An arcade of Struthers was present in 26 specimens and Osborne’s ligament was present in all specimens. A discrete flexor pronator aponeurosis overlying the ulnar nerve was present in 17 specimens. An average of one (range, 0–3) capsular nerve branches were noted. These originated an average 7 mm proximal (range, 45 mm proximal to 24 mm distal) to the medial epicondyle. An average of three (range, 1–6) motor branches to the flexor carpi ulnaris muscle were noted, and one of these originated proximal to the medial epicondyle in two specimens. Significant variation was noted in the capsular and motor branching of the ulnar nerve. Care must be taken to identify the motor branches of the ulnar nerve when performing a transposition.

Clinical implications of anatomical wear characteristics in slipped capital femoral epiphysis and primary osteoarthritis

Background: This study compares the wear characteristics in slipped capital femoral epiphysis (SCFE) with those of primary osteoarthritis (OA) in adult patients with advanced arthritis. Methods: One hundred femoral heads and proximal neck specimens were studied from SCFE patients (16 hips) and from primary OA (84 hips) patients undergoing total hip arthroplasties (THA). Grade 4 chondromalacia was plotted on a 2-dimensional (2-D) paper grid. Computer tomographic scans were used to create 3-D models of the femoral head and neck to trace the wear patterns. Results: The SCFE group was characterized by (1) loss of neck-head offset, (2) acetabular neck impingement, and (3) loss of superior peripheral articular cartilage adjacent to superior neck. Whereas the primary OA group showed (1) preservation of head-neck offset, (2) absence of acetabular neck impingement, and (3) preservation of superior peripheral articular cartilage. The 3-D modeling in SCFE specimens demonstrated acetabular impingement on the superior lateral femoral neck causing the femur to externally rotate with flexion. The SCFE patients undergoing THA on average were 11 years younger than those with primary OA. The study strongly suggests that the abnormal rotation of the femoral head in SCFE patients causes thinner superior lateral articular cartilage on the femoral head to articulate with the acetabulum. The pistol-grip deformity of the proximal femur in the SCFE group results in hip impingement, which explains why hip flexion and internal rotation can be restricted. Conclusions: There was a premature development of advanced OA of the adult hip joint in SCFE patients. This was associated with hip impingement caused by loss of the head-neck offset and reorientation of the articular cartilage of the femoral head. Unless the femoral head is redirected in patients with SCFE, the benefits of limited hip preservation debridement procedures are not expected to delay the onset and progression of arthritis. Level of Evidence: Prognostic study

Intramedullary fixation of metacarpal and proximal phalangeal fractures of the hand.

The use of intramedullary fixation for fixation of fractures of the metacarpal and proximal phalanx is reported. Flexible intramedullary rods are used for unstable transverse and short oblique diaphyseal fractures of the proximal phalanx and metacarpal. The fracture site is not opened and the rods are introduced under xray control. The rods are cut flush with the bone so that there is no soft tissue tethering. Intramedullary spacers are used in comminuted metacarpal fractures associated with crush injuries and gunshot wounds. The fracture site is opened and a single rod is placed to fill the intramedullary canal. A supplementary plate may be used to control rotation, and bone graft is usually necessary. A new spacer has been designed that has proximal and distal locking screws to control length and rotation. This also is used routinely with bone graft. The techniques outlined stabilize the fracture site allowing immediate motion postoperatively.

The extensor tendons to the little finger: an anatomic study.

Fifty cadaver hands were dissected to better delineate the extensor tendon anatomy to the little finger. The extensor digitorum communis was present in 35. Of 15 hands without an extensor digitorum communis, 12 had a junctura present. Three hands lacked both extensor digitorum communis and juncturae. Transfer of the extensor digiti minimi tendon in these hands could cause loss of extension to the little finger. Ten hands had a direct attachment of the extensor digiti minimi tendon on the abductor tubercle. Twenty-two hands had either an attachment of the extensor digiti minimi on the abductor tubercle, an unbalanced ulnar slip of the extensor digiti minimi, or both, anatomic factors that could--in the event of ulnar nerve compression or laceration--cause Wartenbergs sign. Twenty-eight hands did not have an anatomic variant of the extensor that could cause ulnar deviation of the little finger.

The innervation pattern of the radial nerve at the elbow and in the forearm

Sixty paired cadaver forearms were dissected to examine the distribution of the radial nerve branches to the muscles at the elbow and forearm. Emphasis was placed on the innervation of the extensor carpi radialis brevis and the supinator muscles because of discrepancies in the literature concerning these muscles. The most common branching pattern (from proximal to distal) was to brachioradialis, extensor carpi radialis longus, superficial sensory, extensor carpi radialis brevis, supinator, extensor digitorum/extensor carpi ulnaris, extensor digiti minimi, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus and extensor indicis. The branch to extensor digitorum and extensor carpi ulnaris came off as a common stem often with the branch to extensor digiti minimi. The branch to the ECRB muscle was noted to arise from the posterior interosseous nerve in 45%, superficial sensory nerve in 25% and at the bifurcation of the posterior interosseous and superficial sensory nerves in 30% of specimens. The supinator had an average of 2.3 branches from the posterior interosseous nerve (range 1–6). The branches to the supinator showed a wide variability proximal to and within the supinator.