Degenerative Changes at the Scaphotrapezial Joint Following Herbert Screw Insertion: A Radiographic Study Comparing Patients with Scaphoid Fracture and Primary Hand Arthritis

Controversies and best practices for acute scaphoid fracture management

Acute scaphoid fractures are common wrist injuries that continue to elicit debate from surgeons regarding the most appropriate diagnostic and management algorithms. This review will examine the current literature and trends, in an attempt to provide the reader with an evidence-based discussion regarding current controversies of interest to clinicians. In addition, an attempt will be made to provide recommendations for the best treatment practices for acute scaphoid fractures.

Transtrapezial Approach for Fixation of Acute Scaphoid Fractures: Rationale, Surgical Techniques, and Results: AAOS Exhibit Selection

The ideal position for a screw used for scaphoid fixation is central. The purpose of this study was to compare the current volar percutaneous approaches used for scaphoid fracture fixation, explore different options to improve central screw placement, and describe our experience with the transtrapezial approach.

Comparison of two percutaneous volar approaches for screw fixation of scaphoid waist fractures: radiographic and biomechanical study of an osteotomy-simulated model

BACKGROUND

When a surgeon uses a percutaneous volar approach to treat scaphoid waist fractures, central screw placement is complicated by the shape of the scaphoid and by obstruction by the trapezium. In this study, we used radiographs and biomechanical tests to compare the standard volar percutaneous approach with the transtrapezial approach, with regard to central screw placement at the distal pole of the scaphoid.

METHODS

Fourteen matched pairs of cadaveric wrists were randomly assigned to two treatment groups. Under fluoroscopic control, a guidewire was drilled into the scaphoid, either through a transtrapezial approach or through a standard volar approach that avoided the trapezium. Guidewire position was measured in the coronal and sagittal planes. A transverse osteotomy was performed along the scaphoid waist, and this was followed by the insertion of the longest possible cannulated headless bone screw. Each specimen was placed into a fixture with a pneumatically driven plunger resting on the surface of the distal pole. Load was applied by using a load-controlled test protocol in a hydraulic testing machine.

RESULTS

All guidewires were inside the central one-third of the proximal pole. The guidewire positions at the distal pole differed significantly between the transtrapezial and standard volar approach groups (p < 0.001). The load to 2 mm of displacement and the load to failure averaged, respectively, 324.4 N (standard error of the mean [SEM] = 73.5 N) and 386.4 N (SEM = 65.6 N) for the transtrapezial approach group compared with 125.7 N (SEM = 22.6 N) (p = 0.002) and 191.4 N (SEM = 36.30 N) (p = 0.005) for the standard volar approach group.

CONCLUSIONS

The data suggest that, in a cadaveric osteotomy-simulated scaphoid waist fracture model, the transtrapezial approach reliably achieves central positioning of a screw in the proximal and distal poles. This position offers a biomechanical advantage compared with central placement in only the proximal pole.

Treatment of delayed/nonunion of scaphoid waist with Synthes cannulated scaphoid screw and bone graft

Fracture of the scaphoid bone is the most common fracture of the carpus, and frequently, diagnosis is delayed. The unique anatomy and blood supply of the scaphoid itself predisposes to delayed union or nonunion. The Synthes scaphoid screw is a cannulated headed screw, which provides superior compression compared with some other devices used to internally fix scaphoid nonunions. Our aim was to conduct a retrospective study looking at the union rate, time to union, and complications and correlating the outcome of treatment against the delay between injury and surgery and location of the fracture within the bone. This study is a review of a cohort of 30 patients treated with a cannulated Synthes scaphoid screw and corticocancellous bone grafting for scaphoid waist delayed union and nonunion at our center. We achieved 86% overall union rate. The patients with delayed union achieved a 100% union rate. Three out of four patients with persistent nonunion after surgery reported no pain and improved function. The failure rate was 75% in patients who had sustained their fracture more than 5 years previously. Our study demonstrates that delayed union of scaphoid waist fractures and scaphoid waist nonunions present for less than 5 years can be successfully treated by fracture compression and bone grafting.

Percutaneous transtrapezial fixation of acute scaphoid fractures

Percutaneous screw fixation of undisplaced fractures of the scaphoid waist has gained popularity but remains technically demanding. This study describes a transtrapezial modification of the volar percutaneous technique and reports the results in 41 patients. The patients were evaluated at a mean of 36 months (range 14-68 months) after surgery. All fractures healed within 10 weeks (mean 6.4 weeks). Functional ranges of wrist motion and grip strength were achieved in all patients. Radiographs showed accurate central placement of the screw in all patients and no degenerative changes were seen at the scaphotrapezial joint. In three patients, the screw was removed because it was prominent at the scaphotrapezial joint.

Clinical and radiological outcome of cast immobilisation versus surgical treatment of acute scaphoid fractures at a mean follow-up of 93 months

We report the outcome at a mean of 93 months (73 to 110) of 71 patients with an acute fracture of the scaphoid who were randomised to Herbert screw fixation (35) or below-elbow plaster cast immobilisation (36). These 71 patients represent the majority of a randomised series of 88 patients whose short-term outcome has previously been reported. Those patients available for later review were similar in age, gender and hand dominance. There was no statistical difference in symptoms and disability as assessed by the mean Patient Evaluation Measure (p = 0.4), or mean Patient-Rated Wrist Evaluation (p = 0.9), the mean range of movement of the wrist (p = 0.4), mean grip strength (p = 0.8), or mean pinch strength (p = 0.4). Radiographs were available from the final review for 59 patients. Osteoarthritic changes were seen in the scaphotrapezial and radioscaphoid joints in eight (13.5%) and six patients (10.2%), respectively. Three patients had asymptomatic lucency surrounding the screw. One non-operatively treated patient developed nonunion with avascular necrosis. In five patients who were treated non-operatively (16%) there was an abnormal scapholunate angle ( > 60 degrees ), but in four of these patients this finding was asymptomatic. No medium-term difference in function or radiological outcome was identified between the two treatment groups.

Incidence of osteoarthritis in the scapho-trapezial joint after Herbert screw fixation of the scaphoid

Twenty patients treated with a Herbert screw for scaphoid fractures (acute or non-union) were reviewed and X-rayed 5-10 years later to assess whether there were degenerative changes in the scapho-trapezial joint due to insertion of the screw. Six had some irregularity in the lateral part of that joint, three of which followed backing-out of the screw. Two others were described as showing irregularity all round the scaphoid but, apart from these, no radiological abnormalities were seen in the central or ulnar part of the scapho-trapezial joint, or on the proximal tip of the scaphoid.

Medium-term results of trapezio-lunate external fixation for scaphoid fractures

We treated 36 scaphoid fractures in 34 patients with trapezio-lunate external fixation. According to the Herbert and Fisher classification, there were 16 type B1, 14 type B2, four type B3 and two type B4 fractures. Trapezial and lunate pins broke in three patients and these were rated as failures. The remaining 33 fractures were followed-up for 3 years and all had excellent outcomes, without signs of arthritis, avascularity or instability.

Percutaneous cannulated screw fixation of acute scaphoid waist fracture

This prospective study assessed the outcome of percutaneous cannulated screw fixation in 49 of 60 acute scaphoid fractures. The union rate was 100% (mean time for radiological union at 12 weeks). There were no early or mid-term complications and all achieved an excellent functional recovery.