Intra-articular distal radius fractures: arthroscopic assessment of radiographically assisted reduction.

The optimal means of assessing articular displacement during closed reduction of distal radius fractures is unknown. The purpose of this study was to evaluate the in vivo accuracy of fluoroscopy (C-arm) and plain radiographs (XR) in measuring articular step-off and gap and to determine if postreduction arthroscopy can identify malreduced intra-articular fractures that would benefit from reduction. Fifteen intra-articular distal radius fractures underwent closed manipulation and percutaneous pinning. Reduction was assessed sequentially by C-arm, XR, and wrist arthroscopy. The width of gapping between articular surface fragments was underestimated to a statistically significant degree by both C-arm and XR. The magnitude of articular step-off measured with arthroscopy was not statistically different than that measured radiographically. In 5 (33%) cases, the optimal reduction obtained using C-arm and XR was found to have an articular displacement of >1mm by adjunctive arthroscopy. Complete reduction and pinning was performed with satisfactory results. These results suggest that adjunctive arthroscopy may detect residual gapping of the articular surface that is not seen by C-arm or XR. Residual displacement noted by adjunctive arthroscopy may prompt another reduction effort and result in an improved articular alignment of intra-articular distal radius fractures.

Arthroscopy of the metacarpophalangeal joint.

The refinement of technology with improved lighting and smaller optics has made possible new techniques of MCP joint arthroscopy. It is the mastery of the unique anatomy of these different--not just smaller--joints, however, that permits the applications of these new skills. Arthroscopy of the MCP joint permits the diagnosis of pathology not well visualized by other means, and the treatment of these lesions with minimal soft tissue disruption. The authors' experience with arthroscopically aided reduction of fractures of the MCP joint has shown it to be as good as or better than open repair of these fractures. The authors have found the same to be true in treating ulnar collateral ligament injuries of the thumb. Although there is a learning curve with small joint arthroscopy, when the team and surgeon are familiar with the new routines and instruments, the time to accomplish the tasks quickly decreases and is often shorter than that for standard open procedures. The authors' experience suggests that the application of these techniques can allow treatment of MCP pathology with fewer complications than open approaches and may result in improved final function.

The management of bone defects of the forearm after trauma.

In summary, the authors believe that traumatic bone defects of the diaphyseal forearm, fewer than 6 cm in length, can be well managed with corticocancellous bone grafting, provided the patient has an adequate soft-tissue envelope. In cases of soft-tissue compromise, primary bone grafting is still the treatment of choice, combined with simultaneous soft-tissue coverage. This does not exclude the use of immediate primary shortening. Traumatic bone defects larger than 6 cm can best be managed with osteoseptocutaneous free fibular graft with excellent functional and cosmetic results. The creation of a one-bone forearm is rarely necessary, but remains a treatment option for an otherwise unsalvageable extremity. Osteo-articular defects can be more difficult to manage. Proximal osteo-articular defects of the radial head can be treated with excision or placement of a titanium radial head prosthesis. Distal osteo-articular defects may be better addressed in the case of radial bone loss by primary wrist fusion and, in the ulna, by a primary Darrach or Suave-Kapandji procedure.

Efficacy of gentamycin-impregnated resorbable hydroxyapatite cement in treating osteomyelitis in a rat model.

OBJECTIVE: To test the effectiveness of a self-setting hydroxyapatite cement (HAC) as a carrier of gentamycin for the treatment of chronic osteomyelitis in a rat model by using a void-fill placement technique. DESIGN: Osteomyelitis of the tibia was created with Staphylococcus aureus (ATCC 49230) in sixty retired female breeder Sprague-Dawley rats by using the model by Korkusuz et al. (J Bone Joint Surg 1993;75B:111-114). At seven weeks after infection, all animals demonstrated clinical and radiographic signs of osteomyelitis and were debrided and divided into four treatment groups: A, debridement only; B, debridement and daily intraperitoneal gentamycin (0.2 milligram per kilogram per day); C, debridement and gentamycin-impregnated HAC in a void-fill model (1.0 milligram per kilogram of gentamycin); and D, debridement and gentamycin-impregnated polymethylmethacrylate (PMMA) beads (1.0 milligram per kilogram of gentamycin). Tibiae were harvested at zero weeks (control, n = 6), three weeks (n = 3 per group), five weeks (n = 4 per group), and seven weeks (n = 4 per group) and analyzed with quantitative bacteriologic analysis. OUTCOME MEASUREMENT: Qualitative bacteriologic analysis was performed by using serial dilution plating of homogenized tissue samples on standard soy trypticase agar plates. Reexamination by phage typing was performed to exclude contamination. RESULTS: The quantitative counts for Groups C (HAC) and D (PMMA) were significantly less (p < 0.003) than those for Group A (debridement alone) or Group B (intraperitoneal gentamycin) at all time points after time zero. There was no difference between Groups C and D at any time point. CONCLUSION: HAC is an effective adjuvant in treating chronic osteomyelitis in a rat model when using a void-fill placement technique.

Effects of calcitonin gene-related peptide on bone turnover in ovariectomized rats.

Calcitonin gene-related peptide (CGRP) is a neuropeptide abundantly concentrated in sensory nerve endings innervating bone metaphysis and periosteum, which indicates that it plays a local role in bone metabolism. CGRP-alpha and -beta share structural and functional homology with calcitonin (CT) and have been shown to inhibit bone resorption in vitro and to induce hypocalcemia in vivo. We recently reported that CGRP stimulates the production of the growth factor insulin-like growth factor-I and inhibits that of the cytokine tumor necrosis factor-alpha by osteoblasts, suggesting that CGRP may control bone cell activity. To investigate this possibility, we used ovariectomized (ovx) rats as a high bone turnover model and compared the effects of CGRP to those of CT. ovx young female rats were injected daily starting the day after surgery with either phosphate-buffered saline, CGRP-alpha (1.15 mg/kg per day), or CT (3 micrograms/kg per day) for 28 days. Ovariectomy induced an increase in bone turnover associated with a 60% loss in trabecular bone volume of the proximal tibia. CGRP inhibited bone resorption but not bone formation, and was nevertheless less efficient than CT in preventing bone loss, since CGRP-treated rats had a loss of 46% of cancellous bone, whereas CT-treated rats had a loss of 21%. This suggests that CGRP is either less potent than CT at inhibiting bone resorption or else very rapidly degraded. These data indicate that CGRP can control bone cells through a mechanism that is in part different from that of CT, and further suggest that CGRP may play a local role in bone metabolism.

Infection following total elbow arthroplasty.

Total elbow arthroplasty can be a safe, effective means of relieving the pain and loss of motion owing to arthritis of the elbow; however, infection is a frequent and devastating complication that occurs in 1 of every 20 total elbows. Through careful patient selection, meticulous operative technique, and vigilant postoperative care, this risk can be decreased. If infection does develop, early, aggressive operative management provides the best hope for salvage of the joint.