Yuk-Leung Wai

The crisscross injury mechanism in forearm injuries

IntroductionA new mechanism of injury of the forearm bones, crisscross injury, is described. It is more common than the Essex-Lopresti fracture dislocation. The old concept of isolated injury of one side of the radioulnar joint may be challenged. It often occurs in Mason type II fracture dislocation of the radial head or dislocation of radioulnar joints.Materials and methodsThe first part was a cadaveric study of the crisscross injury of forearms. The second part was a clinical study of the crisscross injury in some cases of Mason type II fracture radial head and double dislocation of the radioulnar joint.ResultsThe cadaveric study confirmed a stable crisscross fracture dislocation injury with intact interosseous membrane. The clinical study echoed the presence of this injury by imaging techniques.ConclusionThe crisscross injury mechanism explains the mirror pathogenesis of the traumatic fracture dislocation of the distal and proximal radioulnar joints with intact shaft of the radius and ulna. Co-existing subluxation or dislocation of the other radioulnar articulation must not be overlooked in cases of fracture dislocation of one radioulnar joint. Two types of crisscross injury of forearm bones are proposed.

Knee flexion after total knee arthroplasty

Purpose. To identify factors related to knee flexion after total knee arthroplasty in a Chinese population. Methods. Records of 242 total knee arthroplasties were retrospectively reviewed. The parameters evaluated were age, gender, diagnosis, preoperative knee flexion and extension, preoperative flexion arc, tibiofemoral angle, Knee Society knee score and functional score, and implant design. Results. Advanced age, female gender, and good preoperative flexion and flexion arc were related to better postoperative flexion. Postoperative flexion tended to migrate to the middle range despite different ranges of preoperative flexion. Preoperative tibiofemoral malalignment had no significant effect on postoperative flexion. Conclusion. Contemporary designs of posterior stabilised prostheses with right and left femoral components were superior to older designs.

Isolated dislocation of the radial head, with simultaneous dislocation of proximal and distal radio-ulnar joints without fracture in an adult patient: case report and review of the literature.

A 36-year-old female saleswoman presented with left upper limb injury in a landslide in 1999. The falling stones and mud caught her left forearm with the elbow in semi-flexion and pronation position. The left wrist was hyperflexed passively by the rushing mud. The patient described a pronated twisting force on her left forearm associated with severe pain. She also had minor head injury but without loss of consciousness. The Glasgow Coma Scale was normal with no retrograde amnesia. On physical examination, her left elbow was held in flexion and hyperpronation with the wrist in flexion. A superficial abrasion was noted on the dorsal surface of the left forearm. The elbow and wrist were swollen. All movements of the elbow and wrist were limited by severe pain. There was no neurological or vascular injury. Radiography of the forearm (Fig. 1) included the left elbow and wrist joint was taken. It revealed antero-lateral dislocation of the radial head at the radio-capitellar joint, dislocation of the proximal and distal radio-ulnar joints without fracture of the left upper limb. The ulnar head was dislocated volar to the carpus and distal radius while the radial head was volar to the proximal ulna. The ulno-humeral articulation was intact. The forearm bones had a criss-cross appearance on the lateral radiograph. An elbow arthrogram showed some leakage of the contrast from the elbow joint and no intra-articular loose cartilage fragments. Closed reduction was performed under general anaesthesia. The distal radio-ulnar joint reduced with pronation of the forearm but the proximal radio-ulnar joint and dislocated radial head could only be reduced with supination of the forearm. Reduction of one end was repeatedly lost during the manipulation of the other end. Eventually, the distal radio-ulnar joint was reduced by pronation of the forearm and held by compression of the distal ulna against the distal radius with one hand. The forearm was then supinated, reducing the proximal radio-ulnar joint and radio-humeral articulation. Both reductions were stable in neutral rotation and no K-wire was required. There was no diastasis seen at the radio-ulnar joints, we presumed the interosseous membrane was intact. A long arm cast was applied for 5 weeks with the forearm in neutral rotation, 90° of elbow flexion, and the wrist in neutral deviation and 25° of dorsiflexion. A course of physiotherapy and occupational therapy was offered. The patient regained full function and range of movement of the elbow and wrist joints 2 months after the cast was removed. Minor degree of instability of the distal radio-ulnar joint was noticed on rocking the ulnar head against the radius on follow-up at 6 months, but this became stable at 1 year. The patient had full recovery of function.

Blood management protocol for total knee arthroplasty to reduce blood wastage and unnecessary transfusion

Purpose. To compare outcomes of 2 cohorts of patients who underwent total knee arthroplasty (TKA) before and after the introduction of a blood management protocol. Methods. Records of 97 and 96 consecutive patients who underwent unilateral TKA before and after introduction of the blood management protocol, respectively, were reviewed. Before introduction of the protocol, patients were cross-matched for blood before surgery. Transfusion after surgery was at the discretion of the surgeons or the on-call doctors. After introduction of the protocol, only patients with a preoperative haemoglobin level of <110 g/l underwent ‘type and screening’ of blood group. 2 units of blood were cross-matched preoperatively when multiple red-cell antibodies were identified or postoperatively when blood transfusion was required. Only patients with a postoperative haemoglobin level of <80 g/l or being symptomatic received blood transfusion until the haemoglobin level reached >100 g/l. Those with a postoperative haemoglobin level of 80 to 100 g/l were given iron sulphate 300 mg twice daily for a month. Results. The 2 groups did not differ significantly in age, sex ratio, pre- and post-operative haemoglobin levels, and drain output. Comparing outcome before and after introduction of the protocol, the transfusion rate (10.3% vs. 3.1%, p=0.046), cross-match rate (100% vs. 3.1%, p<0.001), and cross-match to transfusion ratio (9.7:1 vs. 1:1, p<0.001) decreased. Among transfused patients, the decreased postoperative haemoglobin level indicated a lower transfusion trigger point (100 g/l vs. 75 g/l, p<0.006) No patient developed infection, cardiovascular or cerebrovascular complications within 30 days. Conclusion. The blood management protocol for TKA is effective in reducing unnecessary allogeneic blood transfusions and wastage of unused blood, without an increase in postoperative complications.

A Prospective Study of Venous Thromboembolic Prophylaxis Using Foot Pumps Following Total Knee Replacement in a Chinese Population

Purpose The purpose of this study was to evaluate foot pumps as mechanical prophylaxis for deep vein thrombosis (DVT) following total knee replacement (TKR) in a Chinese population. Methods All consecutive patients following TKR during 2002–2006 received routine duplex ultrasound surveillance for DVT 9 days postoperatively. The demographic data and risk factors were recorded. No medication was given for DVT prophylaxis in all patients. Results We evaluated 91 consecutive TKRs in 85 patients. Although 44 knee replacements (Group 1) done before December 2004 were not given foot pumps, 47 knee replacements (Group 2) done afterwards were given foot pumps. All patients were followed up for more than 6 months. DVT was detected in three cases (6.8%) in Group 1 compared with four knees (8.5%) in Group 2. Proximal thrombosis was observed in two knees (4.5%) in Group 1 compared with two knees (4.3%) in Group 2. No patient had pulmonary embolism. Six out of 59 (10.2%) patients who underwent the operations under general anaesthesia suffered from DVT, whereas one in 28 (3.6%) patients operated under spinal anaesthesia had DVT. All had no statistical significance. Conclusion The rate of proximal DVT after TKR was low (4.5%) without pharmacological prophylaxis. We advise against the use of pharmacological prophylaxis in Chinese population for TKRs because of the low risk of proximal DVT and its possible bleeding complications. Foot pump did not lower the rate of DVTfurther, and its use for DVT prophylaxis in TKR is not necessary.

Non-union of the triquetrum with pseudoarthrosis: a case report

We report a case of symptomatic non-union of the triquetrum with pseudoarthrosis in a 34-year-old man. Motion of the pseudoarthrosis was noted from radial to ulnar deviation. The patient was treated with bone grafting and screw fixation. The non-union healed and the symptoms subsided. The Mayo wrist score had improved from 65 (fair) to 90 (excellent).