Transfer of a composite island homodigital distal interphalangeal joint to replace the proximal interphalangeal joint. Technique and case report

Ligamentoplasty with interposition of the proximal interphalangeal joint in the treatment of unicondylar osteochondral defects: a cadaveric feasibility study

BACKGROUND

Injuries to the proximal interphalangeal (PIP) joint are common and complex. However, the treatment of osteochondral defects of the head of the proximal phalanx has rarely been described. Herein, we propose a new technique for the management of unicondylar defects of the proximal phalanx that can restore joint amplitudes and provide PIP stability.

METHODS

In this cadaveric feasibility study, unicondylar defects were generated using striking wedges and chisels. First, a transverse tunnel measuring 2 mm in diameter passing through the head of the proximal phalanx was made. A second tunnel at the base of the middle phalanx with the same diameter was then created. The hemitendon of the flexor carpi radialis graft was passed through each of these tunnels. The proximal end of the graft was interposed in the area with a loss of bone substance. The ligamentoplasty was then tensed and fixed by two anchors on the proximal phalanx. Joint amplitudes and frontal stability were measured preoperatively and postoperatively.

RESULTS

There was no significant change in the joint's range of motion: preoperatively, the mean mobility arcs were -2° to 113.80°, and they were -2° to 110° after the procedure (P=0.999). There was no significant difference in joint stability (P>0.05).

CONCLUSIONS

Ligamentoplasty with PIP interposition appears to be a possible solution for the management of unicondylar defects of the proximal phalanx. An evaluation of clinical results is planned in order to definitively confirm the validity of this procedure.

Transplantation of a Free Vascularized Joint Flap from the Second Toe for the Acute Reconstruction of Defects in the Thumb and other Fingers

BACKGROUND

This study aimed to evaluate a novel surgical method for the acute reconstruction of defects in the thumb and other fingers by transplanting a free vascularized joint flap from the second toe and to determine its clinical curative effects.

MATERIALS AND METHODS

A free vascularized joint flap from the second toe was transplanted to reconstruct a complete defect of the thumb and other fingers accompanied by the loss of the proximal finger in 10 patients. Of these patients, three had their thumbs reconstructed with a free vascularized joint flap from the second toe and with the proximal interphalangeal joint flap, one had a thumb reconstructed with a free vascularized joint flap from the second toe, and six had their finger defects reconstructed with the proximal interphalangeal joint flap. The toes of the metatarsophalangeal joint were amputated at the foot donor site. All patients underwent one-stage emergency surgery.

RESULTS

The composite tissue flaps, replanted thumbs, and fingers survived well in all 10 cases. Follow-up visits were conducted for 6-28 months, with an average of 9 months of follow-up. The transplanted bone joints healed over a period of 6-16 weeks. Bone nonunions and refractures did not occur, and the walking function of the foot donor site was not visibly affected.

CONCLUSION

A free vascularized joint flap from the second toe can be transplanted to repair defects in the thumb and other fingers. This technique can be applied to recover the appearance and function of fingers.

[The vascularized articular transfers from the foot]

Complete destruction of the PIP or MCP joint space can be treated by a vascularized transfer from the foot in selected patients. The surgical technique for PIP and MTP vascularised transplantation is described with special emphasis on recent improvements (use of a short vascular pedicle, refinements in donor site reconstruction). Results of a series of 50 transfers performed between 1992 and 2009 are presented. PIP transfer was performed in 37 patients, at an average age of 18.3 years (range 3 to 40) leading to an average active ROM of 44° (0-80), with a lag of extension of 34.2° (0-80). MCP transfer was performed in 12 patients (13 transfers), at an average age of 21.3 years (range 3 to 40) leading to an average range of motion of 60° (35-80), with a lag of extension of 18.6° (0-30). None of the reconstructed articulations was painful. On the plain radiographs, no degradation of the joint space of the transferred articulations was noted. Within the pediatric population, the growth potential was preserved, signing the perenniality of the vascularization of the transfers. When faced to a complete joint destruction involving either the PIP or the MCP of the long fingers, reconstruction can be achieved by the mean of a vascularized joint transfer. The range of motion obtained with these transfers is not superior to what is observed after arthroplasty but it will persist with time. Therefore, even it is a technically demanding option, it should remain in our armamentarium as an alternative to joint fusion or joint arthroplasty.

Morphometric analysis of potential osteochondral autografts for resurfacing unicondylar defects of the proximal phalanx in PIP joint injuries

PURPOSE

This study was designed to morphometrically assess the base of the little and ring finger metacarpals as potential osteochondral donors to resurface distal condylar defects of the proximal phalanx.

METHODS

The proximal phalanges were dissected from all 4 fingers in 10 cadaveric hands and the following measurements were obtained from the distal condylar surface: anteroposterior height, radial-ulnar width, and radius of curvature. Measurements were obtained from posteroanterior and lateral radiographic views, which were digitized and analyzed using digital imaging software. Comparable measurements were obtained from the base of the small and ring metacarpals.

RESULTS

The anteroposterior dimension of both potential donor metacarpals was large enough to resurface the distal condyles of each of the proximal phalanges; however, this was not true for the radial-ulnar dimensions. The distal ulnar condyle of the long finger proximal phalanx was largest, measuring 4.9 (+/- 0.) mm dorsally and 6.2 (+/- 0.5) mm volarly in the radial-ulnar dimension. Only the small metacarpal base had sufficient stock in the radial-ulnar dimension (9.4 [+/- 1.7]) mm dorsally and 10.6 [+/- 2.0] mm volarly) to resurface this condyle. With respect to radius of curvature (ROC), the donor-to-recipient ROC ratio was 1.43 for the small metacarpal base versus 2.12 for the ring metacarpal base. Linear regression analysis revealed a stronger relationship in ROC between donor and recipient condyle when the small metacarpal base served as the donor (R = 0.96 vs R = 0.60).

CONCLUSIONS

As determined from morphometric measurements of the 2 potential donor sites tested, the base of the small metacarpal provides the best match for resurfacing distal condylar defects of the proximal phalanges.

PIP Fracture/Dislocation Treatment Technique: Use of a Hemi-Hamate Resurfacing Arthroplasty

The nature of injury following a PIP fracture dislocation is determined by the direction of force transmission and the position of the joint at the time of impact. Dorsal dislocations with palmar lip fractures are the most frequently encountered and can be classified based on stability. The degree of stability is directly determined by the amount of middle phalangeal palmar lip involvement; the larger the palmar lip fracture, the more unstable the joint becomes. When there is persistent instability or greater than 30 degrees of flexion is required to maintain reduction, treatment must be aimed at reconstituting the cup shaped geometry and buttressing effect of the volar lip of the middle phalanx if stability is to be restored. The use of a hemi-hamate autograft to reconstruct the base of the middle phalanx is a new technique that restores joint congruity and stability while allowing for early motion. This operative technique replaces the damaged palmar lip of the middle phalanx with a size-matched portion of the hamate obtained from its distal dorsal articular surface between the 4th and 5th metacarpals. By restoring both articular congruity and osseous stability the advantage of this procedure is that it allows more immediate rehabilitation with a potential for earlier motion, less stiffness and possibly less post-traumatic arthritis.