Locking of the metacarpophalangeal joint: A comprehensive review of the literature.

Locked metacarpophalangeal joint is an uncommon phenomenon with many possible etiologies. Diagnosis can be difficult because of the many more common pathologies (trigger finger, sagittal band lesion, etc.) that can lead to a clinical picture that may resemble the locked metacarpophalangeal joint. Once the differential diagnoses have been eliminated, the etiology of this blockage must be determined and the surgical procedure must be oriented. The origin of the problem is often difficult to determine, especially since standard imaging tests are often not very informative. Several clinical forms are possible, with blockages in extension or flexion, but which will have a disabling functional impact on the overall function of the hand. Currently, there is no gold standard for the management of this condition. In this study, we performed a review of the literature in order to better understand the different possible etiologies but also to analyze the different diagnostic and therapeutic management. LEVEL OF EVIDENCE: IV.

Restoration of the first dorsal interosseous muscle.

Motor dysfunction of the 1st dorsal interosseous (DIO) muscle is typically observed in low and high ulnar nerve palsy. This causes weak thumb-index pinch, which can be disabling for the patient. Various reconstructive techniques have been described; however, the choice often depends on the surgeon's experience, the presence of associated neurovascular and musculotendinous injuries, as well as the requirements of the palliative surgery schedule. Nerve transfers can be proposed when patients present early in the course of the disease. Tendon transfers are often a last resort when late presentation occurs. Tendon transfers must follow general principles: the insertion is made on the 1st DIO terminal tendon; the tension must be adjusted in a neutral position to avoid excessive tension, and immobilization is maintained for 4 weeks. Although many transfers are possible, the extensor pollicis brevis transfer is our preferred option. This donor does not require additional tendon grafting, has a direct line of pull close to that of the 1st DIO and is not often used for other reconstructive purposes.

The two-stage free flap strategy: An alternative to reconstruct major oncological surgical defects with noble organ exposure.

BACKGROUND: To minimize the risk of viscera exposure for parietal or calverial reconstruction after tumor removal, we used the two-stage free flap strategy. The flap was transferred a few days before tumor resection and left in a standby position until the second stage. PATIENTS AND METHOD: We conducted a retrospective monocentric study. All patients who underwent reconstruction with the two-stage free flap strategy after tumor resection since 2000 were included. RESULTS: We performed 14 two-stage flaps (8 for calvaria, 3 for abdomen, and 3 for thorax) on 12 patients. The average skin paddle surface was 318 cm2. The mean operative time was 274min for the first stage and 172min for the second stage. The average time between the two stages was 8.8 days (2 to 24 days). One flap necrosis, one venous thrombosis, and one hematoma were observed after the first stage. Partial skin paddle necrosis (2 flaps) and infections (3 flaps) occurred after the second stage. The mean follow-up was 20 months (6 to 61 months), and two patients had tumor recurrence. CONCLUSIONS: The two-stage free flap strategy is another option for major oncological reconstructions, to be safe and reliable some rules must be followed. The flap must contain a large skin paddle to ensure flap autonomization and to allow for complete tight plication of the flap between the two stages, which limits germ colonization. A short delay between the two stages (<12 days) decreases the risk of infection. The presence of a plastic surgeon during the second stage decreases the risk of pedicle trauma.

Arm reconstruction.

The arm is less often concerned by reconstructive surgeries than more distal parts of the upper extremity. However, when affected, the arm is frequently part of complex mutilating injuries involving composite defects. For a given traumatic or oncologic defect, there are several reconstructive options and choosing the right sequence may pose a challenge even to the most experienced surgeon. The latter must integrate not only functional and esthetic requirements, but also the surgeon's habits, especially in situations of emergency. Once life-threatening conditions are averted, wound debridement, bony stabilization, neurovascular, and cutaneous reconstruction tailored to the defects should be performed in a single-stage procedure. Functionally, prompt bony stabilization is necessary to allow early mobilization. Diaphyseal shortening of the humerus can be a salvage procedure to avoid nerve and vascular grafting, with good biomechanical tolerance up to 5cm. Restoration of adequate elbow motion sometimes requires muscle transfer and should be a main concern, as proper positioning of the hand during daily activities demands a functional elbow joint. Esthetically, the surgeon must choose the most cosmetic skin coverage option whilst limiting morbidity of the donor site area. The flaps vascularized by the sub- scapular or thoraco-dorsal vessels are the most useful flaps for arm reconstruction. This paper discusses the reconstructive sequence of complex defects of the arm and provides a review of commonly used reconstructive techniques supported with illustrative cases.

Biomechanical causes of trapeziometacarpal arthroplasty failure.

Trapeziometacarpal joint prosthesis revision has been widely reported, mainly due to loosening of the trapezium cup. Our hypothesis is that current prostheses do not sufficiently respect the kinematics of this joint. CT scan acquisitions enabled us to determine the position of the first metacarpal relative to the trapezium in three different characteristic postures, in subjects in different stages of arthrosis. A CAD model of a current prosthesis was inserted into the numerical 3D model of the joint under the different postures. In the numerical model, we observe penetration of the cup by the head of the prosthesis. This virtual penetration could, in vivo, amount to overstressing the prosthetic elements, which would lead to loosening of the cup or of the metacarpal stem and luxation of the prosthesis.