Participation of human superficialis flexor tendon segments in repair in vitro.

We analyzed the healing capability of the human superficialis (sublimus) flexor tendon in response to injury in vitro by performing a morphologic study of tendon repair. Tendon segments were cultured in cell-free medium for 2, 4, or 8 weeks, and the cut-end repair sites were compared with those in fresh control segments on light and electron microscopy. Tendon encapsulation had occurred at 2 weeks, by the proliferation and migration of elongated fibroblasts from the epitenon and from collagen bundles of the endotenon to cover the surface of the cut tendon ends. As migrating epitenon cells approached the cut margin, they consistently shifted from a parallel to a circumferential orientation with respect to the tendon axis. By 4 weeks, the encapsulating surface cells had lost their membranous ruffles and had become flattened. Within the capsule, phagocytic cells engulfed collagen debris, and fibroblasts containing extensive rough endoplasmic reticulum profiles and secretory vesicles participated in protein synthesis. The surface of the capsule was smooth and, at 8 weeks, was almost indistinguishable from the epitenon surface of uncultured controls. The capsule now had a collagen-synthesizing layer of fibroblasts superimposed on layers of maturing collagen bundles that separated resting-phase fibroblasts. These findings demonstrate that segments of human superficialis flexor tendons participate in an intrinsic repair response without contributions from extrinsic cells.

Histiocytic lymphoma (reticulum-cell sarcoma) of bone. Current strategy for orthopaedic surgeons.

We retrospectively reviewed the cases of eight patients with histiocytic lymphoma (reticulum-cell sarcoma) appearing as a primary bone lesion. Histological findings were classified according to the criteria of Rappaport. Lesions were staged as suggested by the Ann Arbor Conference. After thorough staging, four of the eight patients were shown to have more extensive disease than was initially thought, which altered the therapeutic approach used. Thorough staging is necessary for improved survival of patients with histiocytic lymphoma of bone. We suggest a diagnostic strategy for patients with histiocytic lymphoma presenting in bone that leads to appropriate therapy.

The effect of a thigh tourniquet on the incidence of deep venous thrombosis after operations on the fore part of the foot.

We performed a prospective randomized clinical study to determine whether use of a thigh tourniquet influences the incidence of deep venous thrombosis. The lower limbs of patients who were scheduled for elective surgery on the fore part of the foot were randomized and assigned to one of three treatment categories: Group I, no tourniquet; Group II, exsanguination by an Esmarch bandage before tourniquet application; and Group III, exsanguination by elevation of the extremity prior to application of a tourniquet. The 117 limbs of seventy-one patients included in this study were evaluated preoperatively and twenty-four and seventy-two hours postoperatively with 125I-labeled fibrinogen, and preoperatively and seventy-two hours postoperatively with Doppler ultrasound studies and phleborheography. The findings in all of the Doppler ultrasound studies and all of the phleborheograms were normal. Two of the 125I-fibrinogen studies were positive, but subsequent contrast venography revealed that these were false-positive findings. We therefore concluded that the use of a thigh tourniquet does not increase the risk of deep venous thrombosis in patients who have had an operation on the fore part of the foot.

Hand injury patterns in softball players using a 16 inch ball.

Softball is a popular recreational and competitive sport among both men and women. The injury rate in softball players is as high as that in baseball and basketball players. We conducted a retrospective analysis of 119 hand injuries in 108 patients treated at the University of Chicago hand clinic. All of the injuries were caused by the impact of a 16 inch circumference softball. Of the 119 injuries, 87 (73%) had bone involvement. Operative treatment was required in 26 (22%) injuries, 23 involving fractures and 3 involving soft tissue only. There was one (3.8%) operative complication. Of all injuries, 101 (86%) involved the finger joints, including 46 (39%) injuries to the distal interphalangeal (DIP) joint, 48 (40%) to the proximal interphalangeal (PIP) joint, and 7 (6%) to the metacarpophalangeal (MCP) joint. The most common DIP joint injury was a mallet injury. This fracture, the most common single type of injury in our series, accounted for 27% of all injuries. Of all mallet injuries, 86% were fractures. The most common PIP joint injury was a volar plate fracture, the second most common injury in our series. Variables such as the patient's sex, dominance or nondominance of hands, and early or late season play were not associated with a higher risk of injury. Certain parts of the hand, such as the more ulnar digits and the DIP and PIP joints, were at particularly high risk of injury.

Operation for collateral ligament ruptures of the metacarpophalangeal joints of the fingers.

Ten cases of complete rupture of the collateral ligaments of the metacarpophalangeal finger joints are reported. The nature of this injury, the pre-operative morbidity and the intra-operative pathology are analysed. In all cases surgery was performed with satisfactory results. Operation is indicated for joint stability, grip and pinch strength, pain control and early functional recovery.

Treatment of painful hand neuromas by their transfer into bone.

Painful neuromas in the hand are not only very disabling for the patient, but difficult to treat. We present the results of 20 painful neuromas treated by burying the neuroma in the bone. Eighteen of the 20 neuromas operated on had acceptable results, according to the criteria of Herndon et al. We present our technique and compare our results with other treatments in the literature.

Full-thickness skin wound explants in tissue culture: a mechanical evaluation of healing.

This study was designed to evaluate biomechanically defined wound healing in full-thickness skin explants in tissue culture. The requirement for preculture incubation of wounds in situ was characterized. Full-thickness skin incisions were made in 44 rats and closed immediately. Wounds were incubated in situ for 0, 12, 24, 36, 48, 72, or 96 hours before harvesting and placement into tissue culture media for 6 weeks. Healing was evaluated by biomechanical criteria: tensiometric distraction to wound rupture generated true stress and energy absorption data. Burst-strength (maximum true stress) and toughness (energy absorption) were five times higher in the 48-hour group than in any other group; other groups were not different from each other. This study demonstrates long-term survival of full-thickness skin in culture and shows that full-thickness skin explants heal in tissue culture. Possible explanations for the narrow window of opportunity for harvest (48 hours, no more and no less) are discussed.

A randomized prospective study of polyglycolic acid conduits for digital nerve reconstruction in humans.

This article reports the first randomized prospective multicenter evaluation of a bioabsorbable conduit for nerve repair. The study enrolled 98 subjects with 136 nerve transections in the hand and prospectively randomized the repair to two groups: standard repair, either end-to-end or with a nerve graft, or repair using a polyglycolic acid conduit. Two-point discrimination was measured by a blinded observer at 3, 6, 9, and 12 months after repair. There were 56 nerves repaired in the control group and 46 nerves repaired with a conduit available for follow-up. Three patients had a partial conduit extrusion as a result of loss of the initially crushed skin flap. The overall results showed no significant difference between the two groups as a whole. In the control group, excellent results were obtained in 43 percent of repairs, good results in 43 percent, and poor results in 14 percent. In those nerves repaired with a conduit, excellent results were obtained in 44 percent, good results in 30 percent, and poor results in 26 percent (p = 0.46). When the sensory recovery was examined with regard to length of nerve gap, however, nerves with gaps of 4 mm or less had better sensation when repaired with a conduit; the mean moving two-point discrimination was 3.7 +/- 1.4 mm for polyglycolic acid tube repair and 6.1 +/- 3.3 mm for end-to-end repairs (p = 0.03). All injured nerves with deficits of 8 mm or greater were reconstructed with either a nerve graft or a conduit. This subgroup also demonstrated a significant difference in favor of the polyglycolic acid tube. The mean moving two-point discrimination for the conduit was 6.8 +/- 3.8 mm, with excellent results obtained in 7 of 17 nerves, whereas the mean moving two-point discrimination for the graft repair was 12.9 +/- 2.4 mm, with excellent results obtained in none of the eight nerves (p < 0.001 and p = 0.06, respectively). This investigation demonstrates improved sensation when a conduit repair is used for nerve gaps of 4 mm or less, compared with end-to-end repair of digital nerves. Polyglycolic acid conduit repair also produces results superior to those of a nerve graft for larger nerve gaps and eliminates the donor-site morbidity associated with nerve-graft harvesting.

Cubital tunnel syndrome: anterior transposition with epicondylar osteotomy.

In this article we reviewed nine consecutive patients operated on for cubital tunnel syndrome. They underwent a modification of the Learmonth procedure in which a medial epicondyle osteotomy was performed. The dissection was completed within intermuscular tissue planes to allow the ulnar nerve to be transposed submuscularly. The medial epicondyle was then replaced and secured using two 4.0 mm AO cancellous screws. This article describes an operative technique, which has not been definitively described previously. Eight of nine patients demonstrated both subjected and objective improvement postoperatively. Eight patients returned to work following surgery. We fell that medial epicondylar osteotomy and screw fixation has minimized operative bleeding, subsequent inflammation, and fibrosis. Immediate range of motion activities have been encouraged, and earlier complete rehabilitation demonstrated.

Human flexor tendon participation in the in vitro repair process.

This work demonstrates that human flexor tendon segments have the same capabilities to survive culturing and to mobilize an intrinsic healing response as previously described animal models. Segments of human flexor profundus tendons from the flexor tendon sheath were cultured in vitro and analyzed at 1, 2, and 4 weeks by scanning and transmission electron microscopy. The epitenon area thickened during the first week of culture. Fibroblasts migrated over the cut surface of the collagen bundles until they encapsulated the cut end by the second week when new collagen fibrils were seen in the extracellular spaces. By the fourth week, cells in multiple layers covered the cut end of the tendon, both collagen fibrils and new mature collagen bundles were seen. End encapsulation was accomplished by fibroblasts migrating from the outer surface and the interstices of the tendon. The encapsulating cells were active in phagocytosis and collagen synthesis during the entire incubation period.

Intrinsic healing of the laceration site in human superficialis flexor tendons in vitro.

The intrinsic capability of the human superficialis flexor tendon to heal a reapproximated laceration site in vitro was examined. Segments of lacerated and sutured human superficialis flexor tendons from zone II were cultured for two, four, or eight weeks in vitro and analyzed by use of light and electron microscopy. We noted a specific pattern of intrinsic healing at the repair site during the incubation period. After two weeks, the cells of the epitenon from both tendon stumps proliferated and appeared to migrate into the repair site. Elongated cells of the thickened epitenon bridged the laceration and synthesized new collagen fibers. By eight weeks, a smooth contiguous tendon surface was restored and the internal collagen bundles were brought into intimate contact. The fibroblasts bridging the laceration, both in the epitenon and centrally in the repair site, were oriented perpendicular to the cut surfaces. The cells in the repair site were active in protein synthesis, and new collagen fibers were present. No cellular necrosis was observed in the internal repair site. Our results indicate that human superficialis tendons possess an intrinsic capacity to heal with diffusion and without dependence on extratendinous cells or on adhesions.

A comparison of four repair techniques for Camper's chiasma flexor digitorum superficialis lacerations: tested in an in vitro model.

The relative strengths of 4 methods for repair of the flexor digitorum superficialis tendon were examined in 14 fresh-frozen cadaver hands (40 tendons). All tendons underwent sharp zone II transection at Camper's chiasma. All transections were repaired with 4.0 Ethibond (Ethicon Inc, Sommerville, NJ) using modified Becker, modified Kessler, horizontal mattress, or simple sutures. Flexion of the repaired digit at a constant excursion rate was rendered up to tendon rupture. The modified Becker technique withstood breaking forces (57.9 N) significantly greater than the other techniques examined. Forces up to 34 N have been measured in vivo during unresisted active finger motion. Thus, the modified Becker technique appears to provide adequate strength for early active flexor digitorum superficialis motion.

Direct-current electrical stimulation of tendon healing in vitro.

The intrinsic capacity of tendons to heal in response to injury has recently been demonstrated by many investigators. Electrical stimulation is often assumed to augment regeneration of various tissues. Using newly developed methods of whole-tendon culture, the authors examined the effect of direct-current electricity on healing in vitro. Deep flexor tendons of rabbits were excised, transected, repaired, and grown in an acellular culture medium for seven, 14, 21, or 42 days. Tendons through which a continuous 7-microAmp current was passed at the repair site were compared with nonstimulated controls. The incorporation of (14C)proline and its conversion to (14C)hydroxyproline was measured at seven days. The mean (14C)proline and (14C)hydroxyproline activities were 91% and 255% greater, respectively, in the stimulated group. The activity was also higher in the stimulated group, by 42 days. Histologic sections showed that intrinsic tenoblastic repair may be enhanced with electrical stimulation in vitro.

The effects of transection and reconstruction of the ulnar collateral ligament complex on the position of the proximal phalanx of the thumb during simulated tip pinch.

Injuries to the ulnar collateral ligament (UCL) of the metacarpophalangeal joint of the thumb are common and may result in functional instability of the joint. Eight cadaveric hands were studied. Physiologic levels of muscle loads were applied to the extrinsic flexor tendon of the thumb to simulate tip pinch of the thumb. We investigated the effects of transection of the UCL and accessory UCL (UCL complex) with and without transection of the dorsal capsule and volar plate and of reconstruction of the UCL, for 2 surgical techniques, on the position of the proximal phalanx with respect to the thumb metacarpal. The spatial positions of the metacarpal and proximal phalanx were measured with a 6 degrees of freedom digitizing system for flexion angles from 0 degrees to 60 degrees in 15 degrees increments. Transection of the UCL complex, dorsal capsule, and volar plate (ulnar capsuloligamentous structures) of the metacarpophalangeal joint did not affect radioulnar deviation or radioulnar shift, but did produce significant increases in supination by 8 degrees and volar translation by 2 mm at 45 degrees and 60 degrees compared with those found for the intact joint. The UCL was reconstructed with a tendon graft using the autogenous extensor digiti quinti. The first surgical technique, a traditional technique, and the second surgical technique, a technique based on anatomy, returned the position of the proximal phalanx on the metacarpal head to normal, with the exceptions of volar translation of the proximal phalanx at 60 degrees and trends toward abnormal supination of the proximal phalanx for flexion angels of 45 degrees and 60 degrees.

Rescue of reapproximated flexor profundus tendons in vitro following segmental irradiation.

Segments of rabbit flexor profundus tendon were transected at their zone II midpoints. Before reapproximation, proximal and/or distal segment halves received 10,000 rads of x-radiation. Four treatment groups were examined with light and electron microscopy after 2, 4, and 8 weeks in culture: group XX had proximal and distal tendon halves irradiated, group PX had only distal tendon halves irradiated, group XD had only proximal tendon halves irradiated, and group PD served as nonirradiated control tendons. After 2 weeks, the epitenons of all nonirradiated segments had proliferated to become several cell layers thick with migratory-type cells. By 4 weeks these cells in groups PX and XD crossed the repair site and invaded the opposing irradiated segments in a previously undescribed pattern. By 8 weeks, bridging and remodeling of the repair site were evident in groups PX and XD, yet not to the extent noted in the nonirradiated control group PD. No histologically evident difference in mechanism or completeness of healing was observed between groups PX and XD, and no comparable proliferation, bridging, or remodeling was observed in the completely irradiated group XX. These observations allowed for conclusions to be drawn regarding regional involvement during intrinsic tendon healing and confirmed the pluripotency of poorly differentiated epitenocytes.

Effect of hyaluronic acid on rabbit profundus flexor tendon healing in vitro.

We performed an in-depth biomechanical evaluation of the effect of hyaluronic acid (HA) on the healing of rabbit profundus tendons cultured in vitro. Seventy-eight flexor tendons from 13 rabbits were transected and reapproximated at their Zone II midpoints. Tendons were divided into left and right forepaw groups. Each tendon from the left forepaw group was incubated in one of four possible culture media: control (no HA), low (0.1 mg/ml), medium (0.5 mg/ml), or high (1.0 mg/ml) HA media. HA was added on the first day of incubation. Each tendon from the right forepaw group was cultured in low, medium, or high concentrations of HA, but HA was added after 1 week of incubation in control media. All tendons were cultured for 8 weeks, after which time tenorrhaphies were disrupted and the following biomechanical parameters were determined: apparent maximum stress, apparent strain at apparent maximum stress, normalized energy absorption, and tangent modulus before failure. Comparisons using these parameters showed no statistically significant differences among the various tendon groups. We believe this is the first study of its kind to show no effect of hyaluronic acid on the functional strength of tendon after healing in vitro.

Dislocation of the hip with traumatic separation of the capital femoral epiphysis: report of a case with successful outcome.

Experience with a successfully treated transepiphyseal fracture-dislocation of the femoral head in a 4-year-old boy, a review of 6 similar injuries from the literature, and consideration of the anatomy of the immature femoral head and neck, suggest that the treatment of choice for this injury is immediate open reduction and internal fixation with a smooth pin followed by cast protection. Contrary to recommendations in the literature, closed manipulation does not seem justified at any time, since it could eliminate residual blood supply to the femoral head by disruption of the soft tissue hinge between the head and neck. In a child, preservation of the blood supply through intra-articular soft parts is even more imperative than in adults.