Joint Distraction for Thumb Carpometacarpal Osteoarthritis: 2-Year Follow-up Results of 20 Patients

A new magnetic internal distractor: cadaveric study of changes in trapeziometacarpal joint forces

Distraction is a new treatment for trapeziometacarpal joint osteoarthritis. The purpose of this study was to test the efficiency of magnetic distraction using a new internal distractor in cadavers. The distractor consists of two magnets embedded inside titanium capsules that are implanted on either side of the trapeziometacarpal joint with the same poles facing each other, so that the force between the magnets distracts the joint. Intra-articular forces were recorded pre-implantation, immediately after implantation and again 10 minutes later. We also studied the changes in the forces before and after the procedure in different thumb positions. Our findings show that the trapeziometacarpal joint could be offloaded in all the studied trapeziometacarpal positions.

Contribution of Soft Tissue Passive Forces in Thumb Carpometacarpal Joint Distraction

Thumb carpometacarpal joint space changes when the surrounding soft tissues including the capsule, ligaments, and tendons are stretched or pulled away. When at rest, joint forces originate from passive contraction of muscles and the involvement of joint capsule and ligaments. Previous biomechanical models of hand and finger joints have mostly focused on the assessment of joint properties when muscles were active. This study aims to present an experimental-numerical biomechanical model of thumb carpometacarpal joint to explore the contribution of tendons, ligaments, and other soft tissues in the passive forces during distraction. Five fresh cadaveric specimens were tested using a distractor device to measure the applied forces upon gradual distraction of the intact joint. The subsequent step involved inserting a minuscule sensor into the joint capsule through a small incision, while preserving the integrity of tendons and ligaments, in order to accurately measure the fundamental intra-articular forces. A numerical model was also used to calculate the passive forces of tendons and ligaments. Before the separation of bones, the forces exerted by tendons and ligaments were relatively small compared to the capsule force, which accounted for approximately 92% of the total applied force. Contribution of tendons and ligaments, however, increased by further distraction. The passive force contribution by tendons at 2-mm distraction was determined less than 11%, whereas it reached up to 74% for the ligaments. The present study demonstrated that the ligament-capsule complex plays significant contribution in passive forces of thumb carpometacarpal joint during distraction.

Involvement in a Personal Injury Claim Is Associated With More Pain and Delayed Return to Work After Elective Nonsurgical or Surgical Treatment for Hand or Wrist Disorders: A Propensity Score-matched Comparative Study

BACKGROUND

A small proportion of patients treated for a hand or wrist condition are also involved in a personal injury claim that may or may not be related to the reason for seeking treatment. There are already indications that patients involved in a personal injury claim have more severe symptoms preoperatively and worse surgical outcomes. However, for nonsurgical treatment, it is unknown whether involvement in a personal injury claim affects treatment outcomes. Similarly, it is unknown whether treatment invasiveness affects the association between involvement in a personal injury claim and the outcomes of nonsurgical treatment. Finally, most studies did not take preoperative differences into account.

QUESTIONS/PURPOSES

(1) Do patients with a claim have more pain during loading, less function, and longer time to return to work after nonsurgical treatment than matched patients without a personal injury claim? (2) Do patients with a personal injury claim have more pain, less function, and longer time to return to work after minor surgery than matched patients without a personal injury claim? (3) Do patients with a personal injury claim have more pain, less function, and longer time to return to work after major surgery than matched patients without a personal injury claim?

METHODS

We used data from a longitudinally maintained database of patients treated for hand or wrist disorders in the Netherlands between December 2012 and May 2020. During the study period, 35,749 patients for whom involvement in a personal injury claim was known were treated nonsurgically or surgically for hand or wrist disorders. All patients were invited to complete the VAS (scores range from 0 to 100) for pain and hand function before treatment and at follow-up. We excluded patients who did not complete the VAS on pain and hand function before treatment and those who received a rare treatment, which we defined as fewer than 20 occurrences in our dataset, resulting in 29,101 patients who were eligible for evaluation in this study. Employed patients (66% [19,134 of 29,101]) were also asked to complete a questionnaire regarding return to work. We distinguished among nonsurgical treatment (follow-up at 3 months), minor surgery (such as trigger finger release, with follow-up of 3 months), and major surgery (such as trapeziectomy, with follow-up at 12 months). The mean age was 53 ± 15 years, 64% (18,695 of 29,101) were women, and 2% (651 of 29,101) of all patients were involved in a personal injury claim. For each outcome and treatment type, patients with a personal injury claim were matched to similar patients without a personal injury claim using 1:2 propensity score matching to account for differences in patient characteristics and baseline pain and hand function. For nonsurgical treatment VAS analysis, there were 115 personal injury claim patients and 230 matched control patients, and for return to work analysis, there were 83 claim and 166 control patients. For minor surgery VAS analysis, there were 172 personal injury claim patients and 344 matched control patients, and for return to work analysis, there were 108 claim and 216 control patients. For major surgery VAS analysis, there were 129 personal injury claim patients and 258 matched control patients, and for return to work analysis, there were 117 claim and 234 control patients.

RESULTS

For patients treated nonsurgically, those with a claim had more pain during load at 3 months than matched patients without a personal injury claim (49 ± 30 versus 39 ± 30, adjusted mean difference 9 [95% confidence interval (CI) 2 to 15]; p = 0.008), but there was no difference in hand function (61 ± 27 versus 66 ± 28, adjusted mean difference -5 [95% CI -11 to 1]; p = 0.11). Each week, patients with a personal injury claim had a 39% lower probability of returning to work than patients without a claim (HR 0.61 [95% CI 0.45 to 0.84]; p = 0.002). For patients with an injury claim at 3 months after minor surgery, there was more pain (44 ± 30 versus 34 ± 29, adjusted mean difference 10 [95% CI 5 to 15]; p < 0.001), lower function (60 ± 28 versus 69 ± 28, adjusted mean difference -9 [95% CI -14 to -4]; p = 0.001), and 32% lower probability of returning to work each week (HR 0.68 [95% CI 0.52 to 0.89]; p = 0.005). For patients with an injury claim at 1 year after major surgery, there was more pain (36 ± 29 versus 27 ± 27, adjusted mean difference 9 [95% CI 4 to 15]; p = 0.002), worse hand function (66 ± 28 versus 76 ± 26, adjusted mean difference -9 [95% CI -15 to -4]; p = 0.001), and a 45% lower probability of returning to work each week (HR 0.55 [95% CI 0.42 to 0.73]; p < 0.001).

CONCLUSION

Personal injury claim involvement was associated with more posttreatment pain and a longer time to return to work for patients treated for hand or wrist disorders, regardless of treatment invasiveness. Patients with a personal injury claim who underwent surgery also rated their postoperative hand function as worse than similar patients who did not have a claim. Depending on treatment invasiveness, only 42% to 55% of the personal injury claim patients experienced a clinically relevant improvement in pain. We recommend that clinicians extensively discuss the expected treatment outcomes and the low probability of a clinically relevant improvement in pain with their personal injury claim patients and that they broach the possibility of postponing treatment.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Distraction Arthroplasty for Basal Thumb Osteoarthritis: 10-Year Follow-Up

PURPOSE

Trapeziectomy has frequently been used to treat basal thumb osteoarthritis. However, complications, such as shortening of the thumb ray and reduced mobility and strength, can occur. The aim of this study was to present a 10-year follow-up of distraction arthroplasty without trapeziectomy.

METHODS

Fifteen patients were followed for a mean of 121 months (range, 121-124 months). Subjective outcomes were evaluated with the Disabilities of the Arm, Shoulder, and Hand questionnaire, while the pain intensity was assessed with a Visual Analog Scale both before surgery and at the end of follow-up. Objective outcomes were obtained using the Kapandji score and an assessment of grip and pinch strength. Preoperative and final postoperative x-rays were obtained to evaluate metacarpal subsidence and progression of trapezial-metacarpal joint arthritis.

RESULTS

The Visual Analog Scale score was reduced from 9.4 ± 0.5 before surgery to 2.5 ± 1 at follow-up. The mean Disabilities of the Arm, Shoulder, and Hand questionnaire score was 75.6 ± 12.6 before surgery and 16.9 ± 4 at 10 years. Hand grip strength of the operated side (26 ± 5.5 kg) achieved 95% of functionality compared to the opposite side, while key pinch strength (6.4 ± 1.6 kg) reached 93%. A Kapandji opposition score of 10 points was found in 12 patients, a score of 9 was found in 1, and a score of 8 was found in 2.

CONCLUSIONS

Distraction arthroplasty of the trapeziometacarpal joint ensures good results in long-term follow-up, when performed in patients with stage I-II basal thumb osteoarthritis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.