Concomitant arthrodesis of the distal interphalangeal joint with surface replacement arthroplasty of the proximal interphalangeal joint: a comparative study in 11 patients

Osteoarthritis (OA) of the hand often affects both the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints simultaneously. Surface replacement (SR) arthroplasty of the PIP joint has been described as an effective surgical option for OA of the PIP joint (Jennings and Livingstone, 2015). If OA is present in both joints, arthrodesis of the DIP and SR arthroplasty for the PIP joints can be performed simultaneously (Jennings and Livingstone, 2015). Little attention has been paid to the effect of simultaneous arthrodesis of the DIP joints on the range of motion (ROM) of the PIP joints after SR arthroplasty. The purpose of this study was to evaluate the effect of simultaneous arthrodesis of the DIP joints on postoperative ROM of the PIP joints, following SR arthroplasty. Eleven SR arthroplasties were performed in eight patients (one male and seven female) (Figure 1). The implant used was the Ishizuki Total Finger System (IFS) (Teijin Nakashima Medical Co., Okayama, Japan), consisting of a titanium proximal phalanx component and a middle phalanx component composed of ultra-high-molecular-weight polyethylene. Mean age at the time of surgery was 68 years (range 60–80), and mean follow-up was 53 months (range 24–72). SR arthroplasty for primary OA was performed on three index fingers, three middle fingers, four ring fingers and one little finger and concomitant arthrodesis of the DIP joint was performed in six fingers (three index fingers, one middle finger and two ring fingers). A dorsal approach was employed for both the DIP joints and the PIP joints (a dorsal Chamay approach) in all cases. DIP joint arthrodesis was performed using an intraosseous wiring technique. Postoperatively, the PIP and DIP joints were maintained in a neutral position with a splint for 7 days and active flexion and passive extension exercises were initiated after 7 days. Outcomes were analysed using the Wilcoxon signed-rank test. When measuring the ROM of the PIP joints alone, the results showed that there was no significant difference before and after SR arthroplasty in all patients. However, the postoperative mean ROM of the PIP joints in patients who had simultaneous DIP joint arthrodesis was significantly larger than those without DIP arthrodesis (Table 1) (p< 0.05). The mean preoperative arc of motion of the DIP joint was not statistically different between the groups, meaning any variations in the results was unlikely to result from the DIP joint. The mean angle for arthrodesis of the DIP joint was 13.3 (range from 0 to 20 ). In hand therapy, a static orthosis is often used to immobilize a joint, to shift motion to an adjacent joint, in order to improve the ROM of this adjacent joint (Jennings and Livingstone, 2008; Bell-Krotoski, 2011). This is a well-known principle in hand biomechanics and in the case of our patients, power of the flexor digitorum profundus tendon is theoretically transferred to the PIP joint when the DIP joint is fused. Our results showed that ROM after PIP joint arthroplasty without arthrodesis of the DIP joint was comparable with previous reports (Jennings and Livingstone, 2015; Murray et al., 2012), but when combined with arthrodesis of the DIP joint, the flexion and arc of motion of the PIP joint was significantly larger. Journal of Hand Surgery (European Volume) 2021, Vol. 46(4) 416–437 journals.sagepub. com/home/jhs