Incidence of re-operation and subjective outcome following in situ decompression of the ulnar nerve at the cubital tunnel.

The purpose of this investigation was to determine the failure rate of in situ decompression for cubital tunnel syndrome as determined by the need for additional surgery. We performed a comprehensive chart review of 56 adult patients who had undergone in situ decompression for cubital tunnel syndrome in 69 extremities with more than 1 year follow-up. The patients completed a comprehensive questionnaire concerning preoperative and postoperative pain, numbness, and weakness. After decompression, symptoms were improved substantially or resolved. Five limbs (7%) with persistent symptoms postoperatively were treated successfully with anterior submuscular transposition. These data suggest that in situ decompression of the ulnar nerve is a reliable treatment for cubital tunnel syndrome and has a low failure rate. The uncommon patient with continued symptoms after decompression can be treated effectively with transposition of the ulnar nerve.

Madelung's deformity: quantitative radiographic comparison with normal wrists.

Four measurements, ulnar tilt, lunate subsidence, lunate fossa angle and palmar carpal displacement, on wrist radiographs of 26 patients with Madelung's deformity and 48 normal subjects were compared. The range of measurements on wrists with Madelung's deformity was wider than on normal wrists, with severe deformities having very abnormal values. Some Madelung's patients had values that were within the normal range for each of the four measurements. Measurement of the lunate fossa angle demonstrated the least overlap between normal wrists and wrists of patients with Madelung's deformity with only two in the normal range. A lunate fossa angle over 29 degrees may help identify early Madelung's deformity.

Trial pinning prior to wrist arthrodesis in children.

The purpose of this investigation was to assess the utility of trial wrist pinning as an assessment tool prior to wrist arthrodesis in the paediatric patient. Ten paediatric patients who were unable to decide if a wrist arthrodesis would be beneficial to them underwent a trial wrist pinning (using temporary K-wires) in neutral posture for an average of 28 days. The etiology of wrist pathology varied. The utility of the trial pining in decision-making was assessed through chart review and telephone conversation. All patients felt the trial pinning facilitated their decision. Two of the 10 patients declined wrist arthrodesis secondary to difficulty with daily activities. Eight patients who underwent wrist arthrodesis were satisfied with wrist position and function. Temporary wrist pinning is an effective informational tool for patients, families and physicians, allowing a true assessment of wrist function prior to definitive wrist arthrodesis.

Anterior elbow release of spastic elbow flexion deformity in children with cerebral palsy.

This study evaluated anterior elbow release for spastic elbow flexion deformity in children with cerebral palsy. Forty-two consecutive surgical procedures are reported in 40 children with a minimum of 1 year of follow-up. The procedure included incision of the lacertus fibrosus, fractional lengthening of the brachialis aponeurosis, and denuding the peritendinous adventitia from the biceps tendon to remove afferent nerve fibers and receptors. Preoperative and postoperative measurements of the flexion posture angle, active extension, and active flexion were obtained, as well as completion of a written questionnaire by the parents. Flexion posture angle improved from 104 degrees before surgery to 55 degrees after surgery, a reduction of 49 degrees; active extension improved from 43 degrees to 27 degrees. There was no significant change in elbow flexion. Before surgery, the average percentage use of the arm was 12%, which improved significantly to 44% after surgery. The authors conclude that anterior elbow release can significantly improve the flexion posture angle and active extension of the elbow, as well as both the functional use and aesthetic appearance of the involved upper limb.

Quantitative variation in vascular endothelial growth factor mRNA expression during early flexor tendon healing: an investigation in a canine model.

Vascular endothelial growth factor (VEGF) is a potent mediator of angiogenesis, with direct mitogenic activity on cells of endothelial origin. We quantified the temporal accumulation of VEGF mRNA at the repair site of an in vivo canine intrasynovial flexor tendon repair and rehabilitation model by means of quantitative Northern blot analysis, in order to detail a molecular signal involved in the intrinsic angiogenic process that accompanies early flexor tendon healing. Significant accumulation of VEGF mRNA occurred at the flexor tendon repair site at 7 days post-operatively, with peak levels seen at post-operative days 7 and 10. Levels returned to baseline by day 14. Local VEGF mRNA accumulation at the repair site temporally precedes and is spatially distinct from the vascular ingrowth itself, which has been shown to occur maximally at day 17. These data suggest that cells within the flexor tendon repair site are involved in molecular processes other than the synthesis of extracellular matrix, such as modulation of angiogenesis.

A comparison of two techniques for digital distraction lengthening in skeletally immature patients.

Since 1987, 16 skeletally immature patients aged 2 to 16 years (mean, 7.9 years) underwent 27 digital lengthening procedures of terminal bones, 20 metacarpals and 7 phalanges, using the distraction callotasis technique. Seven digits were lengthened with 2 fixator half-pins on either side of the osteotomy site (dual half-pin group). Twenty digits, which were too small to accommodate 4 half-pins, were lengthened over a longitudinal intramedullary guidewire with 1 fixator half-pin on either side of the osteotomy site (single half-pin/K-wire group). No bone grafts were needed. The mean preoperative bone length in the dual half-pin group was 30 mm (range, 23-40 mm) and that of the single half-pin/K-wire group was 18 mm (10-30 mm). The mean total length gained was 14 mm (9-23 mm) in the dual half-pin group and 12 mm (6-19 mm) in the single half-pin/K-wire group. The mean percent lengthened was 49% (22% to 96%) in the dual half-pin group and 70% (27% to 136%) in the single half-pin/K-wire group. Eighteen complications occurred: 15 in the 20 cases using the central guidewire (75%) and 3 in the 7 cases without the central guidewire (43%). Only 7 complications required repeat surgery. We conclude that the use of the single half-pin/K-wire technique allows successful and substantial lengthening for bones shorter than 23 mm, making correction surgery possible for younger children. This technique, however, has a greater risk for complications.

BMP-12 gene transfer augmentation of lacerated tendon repair.

Bone morphogenetic protein (BMP) 12 is a recently discovered member of the human BMP family. It is the human homolog of mouse growth/differentiation factor (GDF)-7. Previously we reported that injection of mesenchymal progenitor cells transferred with the BMP-12 gene into the muscles of nude mice induced tendon-like tissue formation. In this study, we further investigated the effect of BMP-12 gene transfer on tendon cells. We observed that adenovirus mediated in vitro BMP-12 gene transfer into chicken tendon cells increased type I collagen synthesis. No change in alkaline phosphatase activity was observed following BMP-12 gene transfer. We also determined that BMP-12 gene transfer into a complete tendon laceration chicken model resulted in a two-fold increase of tensile strength and stiffness of repaired tendons, indicating improved tendon healing in vivo. We conclude that BMP-12 gene transfer is a promising procedure for improving the tendon repair process.

Effect of suture size on locking and grasping flexor tendon repair techniques.

An experimental study was performed using human cadaver flexor tendons to investigate the effect of locking and grasping loop techniques on the tensile properties of repaired flexor tendons, which closely resemble the clinical model. Statistically significant improvement was observed only with the locking loop technique for ultimate and gap strength values using 2-0 core suture and ultimate strength values using 3-0 core suture. There was no statistically significant increase in tensile strength values using 4-0 core suture material. A heavier core suture used with the locking loop technique provided greater ultimate and gap strength of a repaired tendon than when used with the grasping loop technique.

A century of orthopaedic surgery at Washington University. 1899 to 1999.

The 100-year history of orthopaedic surgery at Washington University from 1899 to 1999 is presented. The history focuses on the chairmen, many of whom attained prominence in national orthopaedic organizations, other faculty members, the residency training program, and the affiliated hospitals. Orthopaedic surgery initially was organized as a department, became a division of the Department of Surgery in 1918, and recently again achieved departmental status.

An in vivo study of locking and grasping techniques using a passive mobilization protocol in experimental animals.

An in vivo experimental study was performed on the flexor profundus tendons of adult canines to determine tensile strength differences between locking and grasping technique repairs and to document the tensile strength using a passive mobilization protocol through the first 21 days following surgery. Forty experimental third and fourth flexor tendons of the right forepaws were lacerated and repaired with either of the 2 techniques. The experimental tendons were harvested at days 3, 7, 14, and 21 and were biomechanically tested. The third and fourth profundus tendons of the left forepaws were used as control (day 0) tendons; they were lacerated and repaired with the locking or grasping techniques at the time of harvest and also were biomechanically tested. The locking technique statistically improved tensile strength values at days 0, 3, and 21. The tensile strength decrease was minimal when using a passive mobilization protocol after surgery.

Involvement of ERK in BMP-2 induced osteoblastic differentiation of mesenchymal progenitor cell line C3H10T1/2.

The signaling mechanisms responsible for bone morphogenetic protein (BMP) induced osteoblast differentiation remains poorly understood. Previous research demonstrated that Smad proteins are the substrates and the mediators of BMP bound serine/threonine receptor kinase. In the present study, we examined the possible involvement of extracellular signal-regulated kinase (Erk) in the BMP induced osteoblast differentiation of mesenchymal progenitor cell C3H10T1/2. Our results indicate that BMP-2 inducement increased MAP kinase activity in mesenchymal progenitor cell line C3H10T1/2. Contrary to previous reports, this increased MAP kinase activity showed a latent but sustained pattern. Elevation of Erk1 and Erk2 protein levels was observed simultaneously. RT-PCR results demonstrated that the elevation of Erk protein level in BMP-2 induced cells was from the upregulation of mRNA expression. Furthermore, upregulated Erk proteins present enhanced phosphorylation. By using a dominant-negative Erk2 cell line, we demonstrated that nonfunctional Erk2 partially eliminated BMP-2 induced cell proliferation and ALP activity in the C3H10T1/2 cell. These results indicate that Erk is involved in BMP-2 induced osteoblast differentiation. The results also demonstrate that a latent and sustained signaling pattern exists in BMP induced signaling cascade.

The spectrum of radial longitudinal deficiency: a modified classification.

The records of 119 patients with 196 extremities with radial longitudinal deficiency seen between 1923 and 1996 were reviewed. We propose a global classification system that includes the spectrum of pathology affecting the radial side of the extremity, including deficiency of the radius, carpal abnormalities, and hypoplastic thumbs. Radial deficiency could be classified for 181 extremities of 104 patients using this classification system. Type N has a normal length radius and a normal carpus with thumb hypoplasia, type O has a normal length radius and radial side carpal abnormalities, type 1 has more than 2 mm shortening of the radius, type 2 has a hypoplastic radius, type 3 has a partial radius with absence of the distal physis, and type 4 has complete absence of the radius. All patients had thumb hypoplasia. Eighty-two percent of extremities with thumb hypoplasia but no deficiency of the radius that were available for carpal bone classification had carpal anomalies, including absence, hypoplasia, and coalitions. All the extremities with type 1 radial deficiency had carpal anomalies. Carpal abnormalities could not be determined for types 2, 3, and 4 deficiency because most had a prior centralization. Proximal radioulnar synostosis or congenital dislocation of the radial head was seen in 44% of extremities with type 1 radial deficiency. This classification includes carpal anomalies and thereby links isolated thumb hypoplasia and deficiency of the radius into one system.

Effect of bone morphogenetic protein-12 gene transfer on mesenchymal progenitor cells.

Recombinant adenovirus mediated human bone morphogenetic protein-12 gene transfer induced tendon and cartilage-like tissue formation in vivo. The recombinant adenovirus with the human bone morphogenetic protein-12 gene was constructed, and mature human bone morphogenetic protein-12 expression mediated by adenovirus gene transfer was detected by specific antibody. Unlike bone morphogenetic protein-2 gene transfer, bone morphogenetic protein-12 gene transferred mesenchymal progenitor cell line C3H 10T1/2 showed no change of alkaline phosphatase activity, which is the mark of cell differentiation into osteoblastic phenotype. Injection of bone morphogenetic protein-12 gene transferred C3H 10T1/2 cells into nude mice thigh muscles induced tendon and cartilage-like tissue formation. The results indicate bone morphogenetic protein-12 has different effects on mesenchymal progenitor cell differentiation, and it may influence the cell differentiation into a nonosteoblast lineage.

Effect of the cross-sectional area of locking loops in flexor tendon repair.

An experimental study was performed using human cadaver flexor tendons to determine whether the size of the cross-sectional area encompassed by the locking loop suture configuration affected the biomechanical properties of tendon repair. Increasing the cross-sectional area of the locking loops from 10% to 50% resulted in a proportionate increase in the ultimate tensile strength of the repair and a small increased propensity for gapping. Overlapping the 2 locking loops without increasing the total cross-sectional area increased the propensity for gapping without increasing the ultimate strength.

Gene therapy: adenovirus-mediated human bone morphogenetic protein-2 gene transfer induces mesenchymal progenitor cell proliferation and differentiation in vitro and bone formation in vivo.

This study reports that recombinant adenovirus-mediated human bone morphogenetic protein-2 gene transfer can induce mesenchymal progenitor cell differentiation and bone formation. The recombinant adenovirus with the human bone morphogenetic protein-2 gene was constructed, and mature human bone morphogenetic protein-2 expression mediated by adenovirus gene transfer was detected by specific antibody. Under adenovirus-mediated bone morphogenetic-protein gene transfer, mesenchymal progenitor cell line C3H/10T 1/2 showed cell proliferation dependent on adenovirus bone morphogenetic-protein dose. The C3H/10T 1/2 cells transduced by adenovirus bone morphogenetic protein also exhibited differentiation to osteoblast phenotype, which indicates alkaline phosphatase activity. Injection of the C3H/10T 1/2 cells into the thigh muscles of nude mice led to ossicle development detectable on radiographs. Histological analysis indicated that the new ossicles that developed in the thigh muscles of the mice had different osseous components including bone trabeculae, bone marrow, and chondrified tissue. The results of this study demonstrate the potential for gene therapy by adenovirus-mediated bone morphogenetic-protein gene transfer.

Management of forearm deformity in multiple hereditary osteochondromatosis.

The records of 97 patients with multiple hereditary osteochondromatosis were retrospectively reviewed. Seventy-eight patients had one or more osteochondroma(s) of one or both forearm(s). Fifty-three operations were performed, of which 41 were excisions of symptomatic osteochondromas or dislocated radial heads. All forearm, wrist, and elbow radiographs were reviewed. Four common radiographic parameters were measured: radial articular angle, carpal slip, relative ulnar shortening, and forearm-third metacarpal angle. Thirty-seven of these 78 patients were contacted by telephone questionnaire. The results indicated that skeletally mature patients do well on a functional basis and are comfortable with their appearance, despite deformity. Surgery can improve aesthetic appearance and provide pain relief when done before or after skeletal maturity. Because of these results, we are less aggressive in the early treatment of forearm deformities.