Silicone arthroplasty for nonrheumatic metacarpophalangeal joint arthritis.

PURPOSE: To evaluate the clinical effectiveness of metacarpophalangeal (MCP) arthroplasty for nonrheumatic arthritis. We hypothesized that MCP arthroplasty would produce significant improvement in objective measures of hand function, pain relief, and overall patient satisfaction. METHODS: This retrospective study evaluated 30 patients with 38 MCP arthroplasties for nonrheumatic arthritis over a 12-year period. Follow-up assessment was completed at an average of 56 months after surgery. Objective measures included range of motion; grip and pinch strength; Disabilities of the Arm, Shoulder, and Hand (DASH) score; and visual analog pain score. A subjective patient questionnaire was used to assess patient satisfaction. RESULTS: There was marked improvement between preoperative and follow-up range of motion, DASH, and pain. Linear regression showed strong correlations between preoperative measurements and improvement at follow-up. No difference was detected for grip or pinch strength. Results of the questionnaire showed that 73% were very satisfied, 87% would definitely do it again, and 70% experienced rare or no pain. Follow-up x-rays showed 5° mean angulation and 2-mm mean subsidence compared with immediate postoperative x-rays. Four arthroplasties (11%) required revision. CONCLUSIONS: This study showed improved range of motion and DASH score, excellent pain relief, and excellent patient satisfaction in patients undergoing MCP arthroplasty for nonrheumatic arthritis. Patients with more severe range of motion limitation, DASH score, and pain score experienced a greater improvement of these measures at follow-up. Strength improvement was limited although it remained comparable to the nonoperated hand. Angulation, subsidence, and complications in the study population were consistent with those reported in the literature. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

In vitro corrosion analysis in low-intensity, pulsed ultrasound.

Clinical investigations have demonstrated a reduced time to union in certain fractures whose management is augmented with low-intensity ultrasound. It is hypothesized that ultrasound augmentation is attributable to mechanical stimulations at the cellular level. Additionally, mechanical stimulation of various magnitudes affects the corrosion rate of metals. Therefore, the effect of ultrasound on the corrosion properties of orthopedic implant materials warrants evaluation prior to recommending ultrasound as an adjunctive treatment for fractures in the presence of internal fixation devices. The purpose of this study was to determine whether low-intensity ultrasound adversely affects the corrosion properties of 316L stainless steel, a commonly used metal in surgical implants. An electrochemical cell was used to expose 316L stainless steel specimens to a corrosion environment. Experimental specimens were subjected to low-intensity ultrasound at the clinically applied intensity. Polarization curves were used to extract average corrosion current density in the passive region, primary passive potentials, and transpassive potentials. Analysis revealed no significant differences between the experimental and control corrosion current density, primary passive potentials, or transpassive potentials. Based on this in vitro analysis, we demonstrated no significant difference in corrosion rate between controls and exposed samples. We conclude that low-intensity ultrasound has no adverse effect on the corrosion properties of stainless steel implant materials.

Treatment of clubfoot with the Ponseti method: a comparison of casting materials.

BACKGROUND: Popular initial treatment for congenital clubfoot includes the use of serial manipulations and casting as described by Ponseti et al. Plaster of Paris and semirigid fiberglass are 2 materials commonly used for casting. To our knowledge, no study to date has compared the clinical results of these 2 materials. The objective of this randomized prospective study was to compare the effectiveness of these materials in the initial management of clubfoot. METHODS: All clubfeet presenting to the 2 senior authors' outpatient clinics over a 15-month period were offered enrollment. Patients were randomly assigned for treatment with either plaster or semirigid fiberglass casts. The severity of the clubfoot deformity was documented using the scoring system devised by Diméglio et al. Serial casts were applied according to the technique described by Ponseti et al. At the completion of nonsurgical treatment, the final clubfoot severity was documented. RESULTS: A total of 42 clubfeet in 34 patients were enrolled in the study. After exclusion of 3 patients, 13 patients (16 feet) received fiberglass, and 18 patients (23 feet) received plaster casts. The mean baseline severity scores of the 2 groups were not significantly different. The mean final severity score was significantly higher in the feet treated with fiberglass than those treated with plaster (6.4 vs 4.1; P = 0.037). There was a trend toward higher scores for cast tolerance, durability, and parent satisfaction in the fiberglass group, but this did not reach significance. CONCLUSIONS: This study supports the use of plaster casting with the Ponseti technique. The use of plaster casts resulted in a statistically lower Diméglio-Bensahel score at the completion of serial casting. There was a trend toward higher patient satisfaction in the fiberglass-treated group. Whether this difference has an effect on long-term outcomes and recurrence remains to be studied. LEVEL OF EVIDENCE: Level II. Nonblinded randomized controlled prospective study.