Minimally Invasive Versus Open Hammertoe Correction: A Retrospective Comparative Study.

Hammertoe deformity is a common forefoot pathology, characterized by a progressive deformity with dorsiflexion of the proximal phalanx on the metatarsal head at the metatarsal phalangeal joint (MTPJ) and plantarflexion of the intermediate phalanx on the proximal phalanx at the proximal interphalangeal joint (PIPJ). While there is literature available discussing open techniques for hammertoe correction, there is a lack of publications discussing minimally invasive techniques, therefore the objective of this retrospective comparative study is to evaluate minimally invasive versus open hammertoe surgery in terms of time to osseous union, complications, recurrence, and return to full activity. Sixty eight feet among 41 patients met the inclusion criteria and were surveyed. Among the 68 feet, 54 feet (124 toes) underwent minimally invasive hammertoe correction and 14 feet (22 toes) underwent open hammertoe correction. Time to osseous union (weeks) in the MIS group was 8.76 ± 2.31 weeks with similar outcomes to the open group with union at 8.42 ± 2.31 (p = .65). Return to activity (weeks) was 10.47 ± 3.45 in the MIS group and 9.92 ± 3.03 in the open group with no statistical significance (p = .62). There was 4 recurrent hammertoe deformities in the MIS group (3.23%) with no recurrent hammertoes in the open group (0%). In the MIS group 5 hammertoes had unplanned hardware removal (4.03%) compared to 0 in the open group. There was no statistical significance for both recurrence and unplanned hardware removal (p = 1). Overall, we concluded that both techniques are equivocal with no detectable statistical difference.

Percutaneous Kirschner Wire Versus Commercial Implant for Hammertoe Repair: A Cost-Effectiveness Analysis.

Hammertoe deformities are one of the most common foot deformities, affecting up to one third of the general population. Fusion of the joint can be achieved with various devices, with the current focus on percutaneous Kirschner (K)-wire fixation or commercial intramedullary implant devices. The purpose of the present study was to determine whether surgical intervention with percutaneous K-wire fixation versus commercial intramedullary implant is more cost effective for proximal interphalangeal joint arthrodesis in hammertoe surgery. A formal cost-effectiveness analysis using a decision analytic tree model was conducted to investigate the healthcare costs and outcomes associated with either K-wire or commercial intramedullary implant fixation. The outcomes assessed included long-term costs, quality-adjusted life-years (QALYs), and incremental cost per QALY gained. Costs were evaluated from the healthcare system perspective and are expressed in U.S. dollars at a 2017 price base. Our results found that commercial implants were minimally more effective than K-wires but carried significantly higher costs. The total cost for treatment with percutaneous K-wire fixation was $5041 with an effectiveness of 0.82 QALY compared with a commercial implant cost of $6059 with an effectiveness of 0.83 QALY. The incremental cost-effectiveness ratio of commercial implants was $146,667. With an incremental cost-effectiveness ratio of >$50,000, commercial implants failed to justify their proposed benefits to outweigh their cost compared to percutaneous K-wire fixation. In conclusion, percutaneous K-wire fixation would be preferred for arthrodesis of the proximal interphalangeal joint for hammertoes from a healthcare system perspective.

Biomechanics and Pinch Force of the Index Finger Under Simulated Proximal Interphalangeal Arthrodesis.

PURPOSE: To analyze the effect of simulated proximal interphalangeal (PIP) joint arthrodesis on distal interphalangeal (DIP) joint free flexion-extension (FE) and maximal voluntary pinch forces. METHODS: Five healthy subjects were tested with the PIP joint unconstrained and constrained to selected angles to produce (1) free FE movements of the DIP joint at 2 selected angles of the metacarpophalangeal joint, and (2) maximal voluntary tip (thumb and index finger) and chuck (thumb, index, and middle fingers) pinch forces. Kinematic data from a motion analysis system, pinch force data from a mechanical pinch meter, and electromyography (EMG) data recorded from 2 flexor and extensor muscles of the index finger were collected during free FE movements of the DIP joint and pinch tests for distinct PIP joint constraint angles. RESULTS: The EMG root mean square (RMS) values of the flexor digitorum profundus (FDP) and extensor digitorum (ED) did not change during free FE of the DIP joint. The extension angle of the range of motion of the DIP joint changed during free FE. It increased as the PIP constraint angle increased. The EMG RMS value of FDP and ED showed maximum values when the PIP joint was unconstrained and constrained at 0° to 20° of flexion during tip and chuck pinch. Neither the index finger metacarpophalangeal and DIP joint positions nor pinch force measurements differed with imposed PIP joint arthrodesis. CONCLUSIONS: The PIP joint arthrodesis angle affects DIP joint extension. A minimal overall impact from simulated PIP arthrodesis in muscle activity and pinch force of the index finger was observed. The EMG RMS values of the FDP and ED revealed that a PIP arthrodesis at 0° to 20° of flexion leads to a more natural finger posture during tip and chuck pinch. CLINICAL RELEVANCE: This study provided a quantitative comparison of free FE motion of the DIP joint, as well as FDP and ED forces during pinch, under simulated index finger PIP arthrodesis angles.

Does distal interphalangeal joint arthrodesis affect proximal interphalangeal joint arthroplasty outcomes in the same finger?

The purpose of this study was to analyse the 1-year outcomes after combining a surface replacing proximal interphalangeal joint arthroplasty and a distal interphalangeal screw arthrodesis and to compare the combined surgery with proximal interphalangeal joint arthroplasty alone. To obtain two groups with similar baseline data from our prospective registry, propensity score matching was used to match 23 fingers with the combined operations with 115 fingers with proximal interphalangeal joint arthroplasty alone. One year after surgery, the mean ranges of motion were 60° (95% CI: 53° to 67°) in the combined group and 63° (95% CI: 60° to 66°) in the control group and did not differ significantly. Grip strength, the brief Michigan Hand Questionnaire and pain also did not differ between the groups 1 year after surgery. All the proximal interphalangeal implants in patients treated with a distal interphalangeal screw arthrodesis remained in situ. Combining proximal interphalangeal joint arthroplasty with distal interphalangeal arthrodesis leads to 1-year outcomes that are similar to those achieved by proximal interphalangeal joint replacement alone.Level of evidence: III.

Functional evaluation of optimal index finger proximal interphalangeal joint fusion angle using a simulated joint arthrodesis.

This study aims at qualitatively and quantitatively evaluating the effects of simulated index finger proximal interphalangeal (PIP) joint fusion angles on hand kinematic function and performance. Although arthrodesis of the index finger PIP joint is an effective medical procedure that produces a durable, pain-free, and stable joint, it permanently immobilizes the joint. Twenty healthy subjects performed basic functional hand activities with the index finger PIP joint unconstrained (UC) and constrained to selected angles under surveillance of a motion capture system. Our results indicate differences in perceived difficulty, time performance, and the functional ROM of the hand joints when the index finger PIP joint is UC and constrained to 0, 20, and 40 degrees of flexion. The mean total perceived difficulty scores for all 6 tasks were higher for the PIP at 0 degrees than for the UC condition (p < 0.001) and for the PIP at 40 degrees (p = 0.048). The functional ROM presented a smaller total number of hand joints affected by the PIP at 20 degrees (25 in total) than the PIP at 0 (31 in total) and 40 (27 in total) degrees during execution of all 6 tasks tested. Therefore, the decision on the appropriate index finger PIP angle for arthrodesis may be between 20 and 40 degrees, as globally for all 6 tasks tested, 0 degrees exhibited the worst results regarding perceived difficulty, performance time, and number of joints with affected ROM. Selecting the appropriate angle for arthrodesis should consider a more complete set of functional activities.

Experimental study of the optimal angle for arthrodesis of fingers based on kinematic analysis with tip-pinch manipulation.

To evaluate the appropriate angle for arthrodesis of the index finger proximal interphalangeal (PIP) joint, the functional range of motion (ROM) of the joints and manipulabilities at three selected tip-pinch manipulation postures of the finger were studied experimentally under imposed PIP joint arthrodesis angles. A kinematic model of the index finger was used in experiments which involved three postures. Experiments were conducted using seven healthy subjects in tip-pinch manipulation tasks to obtain the measurements of finger motions under imposed angles of joint constraint, including the functional ROM of the joints and the three criteria of kinematic manipulability. Data show that the functional ROM and the shape of the kinematic manipulability ellipses at the fingertip were influenced significantly by the imposed PIP joint constraint in the tip-pinch manipulation tests. Results suggest that a PIP arthrodesis angle between 40° and 60° led to the optimal performance of fingers in grasping and manipulation of fine objects. This theoretical and experimental study can help surgeons and clinicians to make more informed decisions on the appropriate constraint angles before the arthrodesis operation, and to customize this angle for individual patients in order to enhance not only the capability of manipulation of the finger but also the quality of life after such intervention.