Margaret Woon Man Fok

The versatile reverse flow sural artery neurocutaneous flap: A case series and review of literature

BackgroundReverse flow sural neurocutaneous flap has been utilized more frequently during the past decade to cover vital structures around the foot and ankle area. The potential advantages are the relatively constant blood supply, ease of elevation and preservation of major vascular trunks in the leg. The potential disadvantages remain venous congestion, donor site morbidity and lack of sensation.MethodsThis descriptive case series was conducted at Queen Mary Hospital, Hong Kong, from 1997 to 2003. Ten patients having undergone reverse flow sural neurocutaneous flap were identified through medical records. There were six females (60%) and four males (40%), with an average age of 59.8 years. The defects occurred as a result of trauma in five patients (50%), diabetic ulcers in four (40%) and decubitus ulcer in one (10%) paraplegic patient. The defect site included non weight bearing heel in four (40%), tendo Achilles in two (20%), distal tibia in two (20%), lateral malleolus in one (10%) and medial aspect of the midfoot in one patient (10%). The maximum flap size harvested was 14 × 6 cm. Preoperative doppler evaluation was performed in all patients to identify perforators and modified plaster of paris boot was used in the post operative period. A detailed questionnaire was developed addressing variables of interest.ResultsThere was no flap failure. Venous congestion was encountered in one case. The donor site was relatively unsightly but acceptable to all patients. The loss of sensation in the sural nerve distribution was transient in all patients.ConclusionReverse sural artery flap remains to be the workhorse flap to resurface the soft tissue defects of the foot and ankle. Anastomosis of the sural nerve to the digital plantar nerve can potentially solve the issue of lack of sensation in the flap especially when used for weight bearing heel.

Volar plate fixation of intra-articular distal radius fractures: a retrospective study.

Background Intra-articular fractures of the distal radius represent a therapeutic challenge as compared with the unstable extra-articular fractures. With the recent development of specifically designed internal fixation materials for the distal radius, treatment of these fractures by fragment-specific implants using two or more incisions has been advocated. Purpose The purpose of this study was to investigate the efficacy of a fixed-angle locking plate applied through a single volar approach in maintaining the radiographic alignment of unstable intra-articular fractures as well as to report the clinical outcomes. We only excluded those with massive comminution, as is discussed in greater detail in the text. Patients and Methods This is a multicentered, retrospective study involving three hospitals situated in Spain, Switzerland, and the United States. In the period between January 2000 and March 2006, 97 patients with 101 intra-articular distal radius fractures, including 13 volarly displaced and 88 dorsally angulated fractures were analyzed. Over 80% were C2/C3 fractures, based on the AO classification. 16 open fractures were noted. Results With an average follow-up of 28 months (range 24-70 months), the range of movement of the wrist was very satisfactory, and the mean grip strength was 81% of the opposite wrist. The Disabilities of the Arm, Shoulder, and Hand (DASH) score was 8. The complications rate was < 5%, including loss of reduction in two patients. All fractures healed by 3 months postinjury. Conclusions Irrespective of the direction and amount of initial displacement, a great majority of intra-articular fractures of the distal radius can be managed with a fixed-angle volar plate through a single volar approach. Level IV retrospective case series.

Chronic Scapholunate Instability Treated With Temporary Screw Fixation

PURPOSE To determine the efficacy of scapholunate (SL) temporary screw fixation to maintain the reduction of SL interval after ligament debridement, repair, or reconstruction. METHODS A total of 36 patients who had chronic SL instability were included. Arthroscopic debridement was performed for dynamic instability, and primary repair or reconstruction of the SL ligament was performed for static instability. We then used SL screw fixation for the protection of the repair or reconstruction. Screws were removed when loosening was noted on x-ray. RESULTS The average patient age was 43 years. Eleven had dynamic instability, and 25 had static instability. The average follow-up was 7.9 years. Nearly 95% of the patients had no more than mild pain. The average ranges of movement of the wrist were 55° extension, 51° flexion, 26° ulnar deviation, and 15° radial deviation. Postoperative x-ray revealed an average SL angle of 56°. The average SL gap was 2.5 mm. Both of these radiographic parameters were maintained at final follow-up. Dorsal intercalated segmental instability (DISI) deformity was not corrected in 2 patients. One patient had avascular changes in the proximal scaphoid and lunate but remained asymptomatic at 7 years postoperatively. There was no further intercarpal and radiocarpal degeneration. CONCLUSIONS Temporary SL screw fixation together with arthroscopic debridement, ligament repair, or reconstruction provided a stable closure of the SL interval and satisfactory clinical and functional results along with a low incidence of complication. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.

Schwannoma in the Upper Limbs

Schwannomas are the commonest tumours of peripheral nerves. Despite the classical description that schwannomas are well encapsulated and can be completely enucleated during excision, a portion of them have fascicular involvement and could not be completely shelled out. A retrospective review for 8 patients was carried out over 10 years. 75% of schwannoma occurred over the distal region of upper limb (at elbow or distal to it). It occurs more in the mixed nerve instead of pure sensory or motor nerve. 50% of patients had mixed nerve involvement. Fascicular involvement was very common in schwannoma (75% of patients). Removal of the tumour with fascicles can cause functional deficit. At present, there is no method (including preoperative MRI) which can predict the occurrence of fascicular involvement; the authors therefore proposed a new system to stratify patients who may benefit from interfascicular nerve grafts. In this group of patients, the authors strongly recommend that the possibility and option of nerve graft should be discussed with patients prior to schwannoma excision, so that nerve grafting could be directly proceeded with patient consent in case there is fascicular involvement of tumour found intraoperatively.

THE BEAUTY OF STABILITY: DISTAL RADIOULNAR JOINT STABILITY IN ARTHROSCOPIC TRIANGULAR FIBROCARTILAGE COMPLEX REPAIR

The triangular fibrocartilage complex (TFCC) has an important role in the stability of the distal radioulnar joint (DRUJ) stability. We designed a new method of TFCC tear repair that has satisfactory post-operative DRUJ stability. From May 2004 to August 2010, 14 patients who underwent this operation were reviewed. The average post-operative follow-up period was 8.2 months; 66.7% of the patients with TFCC tear in sigmoid notch had clinical DRUJ instability, while only 50% of tear in fovea and 16.7% of tear in base of ulnar styloid had clinical DRUJ instability. Transosseous suture via inside-outside technique was used for repair. At the final follow-up, all 14 patients have soft end point with < 5 mm translations of the DRUJ shown by the stress test. Based on this small sample with satisfactory outcome assessed by the Mayo modified wrist score and DRUJ stability, we recommend TFCC tear in sigmoid notch, which has a higher chance of DRUJ instability, to be repaired by transosseous suture.

Autologous osteochondral graft for traumatic defects of finger joints

Finger joint defects in 16 adults were treated with an autologous osteochondral graft from the base of the second metacarpal, the radial styloid, the base of the third metacarpal or the trapezoid and these patients were followed up from between 12 and 62 months. There was no donor site morbidity. One patient had resorption of the graft and developed pain. The joint was subsequently fused. The mean range of movement was 55.8% of the opposite normal joint. At follow up, 15 patients had no discomfort or mild discomfort. Three had mild narrowing of the joint space and two had slight joint subluxation. Only two patients with concomitant severe injury to the same limb had difficulty performing daily activities. Ten were open injuries and these had poorer outcomes. A hemicondylar defect of a finger joint can be treated using an osteochondral graft obtained from the same hand.

CURRENT MANAGEMENT OF HAND ENCHONDROMA: A REVIEW

Enchondromas are benign bone tumours originating from cartilages. It is mainly discovered incidentally in radiographs or due to symptoms like pathological fracture or pain. Conservative treatment through regular check-up and surgical excision using curettage are the two major treatment methods for enchondromas. This review concludes that small localized asymptomatic lesions can be treated conservatively while most expanding or symptomatic lesions should be treated with simple curettage. Adjuvant treatments like high-speed burring or alcohol instillation are not recommended.

Insertional torque and pullout strength of pedicle screws with or without repositioning: a porcine study

Purpose. To evaluate the insertion torque and pullout strength of pedicle screws with or without repositioning. Methods. 20 fresh porcine lumbar vertebrae of similar size were used. The entry point was at the site just lateral and distal to the superior facet joint of the vertebra, and to a depth of 35 mm. A 6.2-mm-diameter, 35-mm-long pedicle screw was inserted parallel to the superior end plate on one side as control. On the other side, an identical screw was first inserted 10° caudal to the superior end plate, and then repositioned parallel to the superior end plate. The insertional torque and pullout strength were measured. Results. Three of the specimens were excluded owing to pedicle fractures during the pullout test. Repositioned pedicle screws were significantly weaker than controls in terms of the maximum insertional torque (3.20±0.28 vs. 2.04±0.28 Nm, 36% difference, p±0.01) and pullout strength (1664±378 vs. 1391±295 N, p±0.01). Conclusion. Repositioning pedicle screws should be avoided, especially when the pedicle wall is breached. If repositioning is deemed necessary, augmentation with polymethyl methacrylate or a screw with a larger diameter should be considered.

A NEW BUILDING BLOCK: COSTO-OSTEOCHONDRAL GRAFT FOR INTRA-ARTICULAR INCONGRUITY AFTER DISTAL RADIUS FRACTURE

Even with the invention of locking plates, intra-articular fractures of distal radius with extreme comminution remain a challenge for orthopaedic surgeons. Osteochondral graft is a potential choice to reconstruct the articular defect. We report a patient who had a fracture of distal radius with costo-osteochondral graft for articular reconstruction which has not yet been described in the English literature. At nine-year follow-up, he was pain free and had full range of movement of the wrist. The authors suggest that costo-osteochondral graft could be an option with satisfactory result.

Midterm Outcomes of the Use of a Spherical Ulnar Head Prosthesis for Failed Sauvé-Kapandji Procedures

PURPOSE The use of a spherical ulnar head prosthesis (UHP) for the treatment of symptomatic radioulnar convergence after Sauvé-Kapandji (SK) procedure has shown promising results in the short term. This study aims to evaluate the midterm outcome of the original cohort of patients treated with this technique. METHODS Seventeen patients with unstable ulnar stumps confirmed both clinically and radiographically were studied. The etiology for the initial SK procedure included posttraumatic distal radioulnar joint (DRUJ) incongruity, primary DRUJ arthrosis, and dysplastic DRUJ. Fourteen of the 17 patients had a minimum of 2, and a maximum of 6, operations prior to having a spherical UHP. All patients suffered from severe pain with difficulty in performing work and daily activities. Ceramic UHP was used for all patients, except 2 in whom a cobalt chrome head was used. RESULTS The average follow-up was 6 years (range, 4-17 years). A marked reduction in pain was observed with 11 patients reporting that they remained pain free. The range of motion of the wrist and power grip was maintained and showed a statistically significant improvement at the late follow-up. The Disabilities of the Arm, Shoulder, and Hand score also significantly improved from 77 to 41. There were no signs of prosthetic loosening at the midterm follow-up. The 2 patients with cobalt chrome prostheses had pain and osteolysis requiring revision to total DRUJ prosthesis. Two patients with dorsal prosthetic subluxation were successfully treated with distal radial osteotomy. CONCLUSIONS The midterm results of ceramic spherical UHP for failed SK procedures in this small patient series are encouraging. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.