Incidence of implant-related complications after arthrodesis of 30 thumb metacarpophalangeal joints with tension-band wires

Comparison of Fusion Rates/Complications Between Different Types of Thumb Metacarpophalangeal Fusion Techniques

BACKGROUND

Thumb metacarpophalangeal (MP) fusion is generally successful; however, complications have been reported to occur in 0% to 30% of cases, whereas nonunion rates vary by method but, overall, are reported to occur in 0% to 15% of cases. Many fixation techniques have been described, but there is no consensus on the optimal fusion technique. Our goal was to compare complication and union rates of different thumb MP arthrodesis techniques.

METHODS

We performed a retrospective review of patients who underwent primary thumb MP fusion between 2000 and 2022. Patients who underwent revision fusion, fusion for infection, or amputation were excluded. Fusions of MP joints of other fingers were also excluded. Data collection consisted of demographic data, complications, time to fusion, rate of delayed union and rate of nonunion. Five different fusion constructs were evaluated during our study period: staples, Kirschner wires (K-wires), cerclage, K-wires with cerclage, and intramedullary screw.

RESULTS

Forty-seven patients underwent fusion with staples, 16 with K-wires, 14 with cerclage, 9 with K-wires and cerclage, and 6 with an intramedullary screw. The individual complication and nonunion rates differed significantly among the groups with the intramedullary screw group having a statistically higher rate of nonunion (P = .004). Furthermore, smoking, diabetes, and being overweight were associated with nonunions.

CONCLUSION

Union rates were significantly lower in patients treated with an intramedullary screw and those who are smokers, diabetics, and/or overweight. Caution should be exercised when using intramedullary screw fixation for MP fusion, especially in patients with these comorbidities.

Union Rates and Complications After Thumb Metacarpophalangeal Fusion

Background: Fusion of the thumb metacarpophalangeal joint (MPJ) can be performed using tension band wiring (TBW) or plate and screw (PS) fixation. This study evaluated results and complications using these techniques. Methods: A retrospective review of patients who underwent thumb MPJ fusion at our institution from 2010 to 2016 was performed. Patients with >1 year follow-up were included. Demographic information, indication for fusion, time to fusion, and complications were collected. Final radiographs were examined and alignment measured. Results: There were 56 thumbs in 53 patients (42 women and 11 men) including 12 TBW and 44 PS. The mean age was 60.9 years, and follow-up was 32.4 months. Twenty-eight of 44 plates were nonlocking, and 16 were locking. Of the locking plates, 7 of 26 used all locking screws, and 9 of 26 had a combination of locked and nonlocked screws. The mean flexion angle for TBW was 16.5° and PS was 12.8°. The mean coronal angle for TBW patients was 4.0° ulnar and PS was 2.5° ulnar. The overall union rate was 95%. There were 12 complications, 9 in the PS group. The TBW complications were painful hardware requiring removal. Eight complications in the PS group occurred in patients with locked plates. Five of the delayed or nonunions occurred in patients with locked plates and 4 of these were in plates with all screws locked. Conclusion: Complications using PS or TBW are not infrequent. Alignment with both techniques is similar, but use of locked plates specifically increases the rate of delayed or nonunions. We do not recommend routine use of locked plates for fusion of the thumb MPJ.

Arthrodesis of the thumb metacarpophalangeal joint: Conventional open technique with a locking plate or compression pins versus minimally invasive technique with compression pins or screws

Arthrodesis of the thumb metacarpophalangeal (MCP) joint usually leads to satisfying results when performed with an open technique. The main complication is adhesion of the extensor tendons that sometimes requires hardware removal associated with tenolysis. The goal of this study was to assess whether a minimally invasive technique could reduce the risk of this complication. Arthrodesis of the thumb MCP was performed using an open technique with a locking plate or compression pins in 12 cases (group I) and using a minimally invasive technique with compression pins or screws in 12 cases, for a total of 24 patients aged 48.9 years on average, among which 15 were women. At the last follow-up, the average pain level was rated at 2/10 in group I and 2.3/10 in group II. The QuickDASH was 40.70/100 in group I and 36.24 in group II, grip strength was 79% of the contralateral side in group I and 51% in group II. Pinch strength was 81% of the contralateral side in group I and 45% in group II. Fusion was achieved in all cases in group I and in 7 of 12 cases in group II. Surgical revision for non-union was needed in 5 cases in group II, with hardware removal and tenolysis performed in 2 cases. The non-unions were observed in non-rheumatoid cases. While the two groups were not identical, arthrodesis of the thumb MCP using a minimally invasive technique with compression pins or screws seems to give satisfying results for rheumatoid cases in which no cartilage remains.