Natural history and pathogenesis of the patella clunk syndrome

INTRODUCTION

The current study aims to test the importance of the design of total knee prostheses in the 'patella clunk syndrome', which is one of the possible patellofemoral complications that can occur after total knee replacement.

MATERIALS AND METHODS

Three patient cohorts consisting of 75 consecutive patients with 80 Insall-Burstein II (IB II) total knee replacements; 57 patients with 60 Anatomic Modular Knee (AMK) total knee replacements; and 103 patients with 106 Low Contact Stress Rotating Platform (LCS) total knee replacements were studied during the period from 1995 to 2001. This was an unselected series of elderly patients with knee arthritis of comparable demographics; we excluded only those patients receiving revision surgery. We recorded the preoperative and postoperative Knee Society scores, and the patient subgroups with postoperative patellofemoral complications were analysed in detail and were serially followed up. Radiological analysis followed the recommendation of the Knee Society, and the degree of pain was recorded on a visual analogue scale. Also, since the majority of patients with patella clunk syndrome had refused operation and were followed up for several years, an idea of the natural history of this condition was obtained.

RESULTS

The relative frequency of occurrence of patella clunk syndrome among patients with the IB II, AMK, and LCS prostheses was 8.8%, 3.3%, and 0%, respectively. The calculated p value is strongly significant when comparing the IB II group with the LCS group (p<0.01); and of borderline significance when comparing the AMK with the LCS group (p=0.05); and not statistically significant between the IB II and AMK groups (p=0.19). Analysis of the results also showed that about half of the patients who underwent conservative treatment still had incapacitating symptoms after several years of follow-up, while the other half showed progressive improvement over time.

CONCLUSION

Given a good surgical technique in component placement and debridement of the peripatella synovium, the design of a total knee prosthesis has a strong bearing on the incidence of the patella clunk syndrome. The natural history of the patella clunk syndrome reveals that for as yet uncertain reasons about 50% will improve with time even when given conservative treatment.

Sacral epidural abscess complicating closed sacral fracture: a case report

OBJECTIVE

To describe the clinical course of the development of an epidural abscess with a rare localization.

SUMMARY OF BACKGROUND DATA

Epidural abscess usually presents with severe back pain and neurologic deterioration. Spinal fracture may lead to the development of epidural abscess. To the author's knowledge, this is the first reported case of epidural abscess following sacral fracture.

MATERIALS AND METHODS

The patient was observed closely in the hospital after a sacral fracture with bilateral S2, S3 dermotome numbness. Fever, bacteremia, and urinary tract infection developed. Fever responded partially with antibiotics.

RESULTS

Sacral laminectomy for decompression was performed. Unexpectedly, sacral epidural abscess was found during the operation. Sacral roots were decompressed. Epidural abscess was drained.

CONCLUSION

A rare case of sacral epidural abscess following sacral fracture was reported.

Distal fixation with Wagner revision stem in treating Vancouver type B2 periprosthetic femur fractures in geriatric patients

Periprosthetic fractures around hip prostheses are difficult problems. We reviewed the results of treatment with Wagner revision stems in geriatric patients (> or = 65 years old) with Vancouver type B2 periprosthetic fractures. Over a 5-year period, 14 patients with Vancouver's type B2 periprosthetic fractures in the proximal femur were revised. The mean follow-up for these patients was 58.5 months (range, 36 to 64 months). The average age was 74.5 years (67 to 83 years). Twelve patients were available for assessment; all 12 reconstructions showed a stable prosthesis and solid fracture union. Seven patients had excellent outcome, 3 had a good outcome, and 2 had a poor outcome. Our series shows that the Wagner revision stem is a satisfactory prosthesis in revision of Vancouver type B2 periprosthetic fractures in geriatric patients.

Duplex ultrasonography after total hip or knee arthroplasty

We prospectively studied all patients admitted for total hip (THR) or knee (TKR) arthroplasty from July 2000 to February 2001. No pharmacological anticoagulation was given. All patients received a standardized postoperative rehabilitation regimen. Forty-six patients with known risk factors for deep vein thrombosis (DVT) were excluded. Eighty patients were studied (22 THR, 58 TKR; 55 women, 25 men). Mean age was 68 (30-90) years. Duplex ultrasonography on both lower limbs was performed on days 5-7 postoperatively. Location and extent of any thrombus were documented. In patients with distal DVT, a follow-up scan was done on days 10-14. If proximal propagation was observed, patients received full anticoagulation. If no propagation was detected, the distal thrombus was considered stable and clinical observation was continued. In the THR group, 1/22 and in the TKR group 9/58 were found to have distal DVT. All were asymptomatic. On follow-up scanning, none showed proximal propagation. All patients were followed up for at least 18 months, and none showed postthrombotic symptoms. Isolated distal DVT in "low-risk" Chinese patients after THR or TKR is not uncommon. Clinically they are usually "silent." If routine perioperative pharmacologic antithrombotic prophylaxis is not practiced, monitoring with duplex ultrasonography may need to be considered.

Deep venous thrombosis after total hip or knee arthroplasty in a "low-risk" Chinese population

Scarcely any information has been published on deep vein thrombosis (DVT) in Chinese patients after total hip arthroplasty (THA) or total knee arthroplasty (TKA). However, generally, no prophylaxis is given to patients who do not have conventional high-risk factors because they are believed to be at "low risk." We performed a prospective study on 80 such "low risk" patients undergoing THA or TKA (58 TKA and 22 THA) without prophylaxis and performed duplex ultrasonography on both lower limbs 6 to 8 days after surgery. A total of 22 patients (27.5%) showed ultrasonographic evidence of DVT. Eighteen (31%) TKAs and 4 (18.1%) THAs were complicated by DVT. Three patients showed bilateral involvement, all of whom underwent TKA. Two patients had symptomatic pulmonary embolism. The sensitivity and positive predictive value of the clinical examination was 27.2% and 31.6%, respectively. This study showed that patients who are labeled "low risk" for DVT actually had a significant risk and suggests that the current practice of providing prophylaxis to only patients deemed at "high risk" should be revised.

Sealing the intramedullary femoral canal with autologous bone plug in total knee arthroplasty

In a prospective study of 262 consecutive patients with total knee arthroplasty, we compared the postoperative suction drainage and transfusion requirement in cases in which the defect made by the femoral intramedullary rod was either unplugged (n = 134) or plugged (n = 128). All operations were performed with a single surgical approach and technique. Inflammatory arthritis and lateral releases were excluded. Blood loss was recorded at 24, 48, and 72 hours. The difference in postoperative suction drainage was not statistically significant. The hemoglobin decrease in the unplugged group (3.5 g/dL) was different from that in the plugged group (2.3 g/dL) (P<.05). Of patients, 64.4% (n = 85) in the unplugged group and 35.9% (n = 46) in the plugged group required transfusion (P<.05). Sealing the femoral canal is effective in reducing hemoglobin decrease and blood transfusion in total knee arthroplasty.

Prognosis of acute pelvic fractures in elderly patients: retrospective study

OBJECTIVE

To analyse the pattern of acute pelvic fractures, prognostic indicators, and intermediate-term functional outcome among elderly patients.

DESIGN

Retrospective study.

SETTING

Community-based hospital, Hong Kong.

PATIENTS

Sixty patients older than 60 years who were admitted to hospital with acute pelvic fracture between 1 November 1993 and 31 December 1996.

MAIN OUTCOME MEASURES

Review of medical records and X-ray assessment to determine the patients' demographic data, medical comorbidities, aetiology and mechanism of injury, associated injuries, and clinical outcome indicators such as complications, duration of hospital stay, ambulatory status, and 1- and 2-year mortality rates.

RESULTS

The mean follow-up period was 29 months (range, 12 to 65 months). Eighty-seven percent of patients were women and the predominant fracture pattern was Tile A2. The leading cause of injury was low-energy fall injury (75%). The 1-year mortality rate was nearly 12%. Thirty-six percent of patients experienced a decline in ambulatory status. Twenty-five percent of superior rami fractures involved the low anterior column of the acetabulum. There was a high incidence of associated cardiovascular disorders.

CONCLUSIONS

Pre-existing medical conditions and acetabular involvement are important adverse factors affecting postinjury ambulatory status. A significant decline in ambulatory status and a significant mortality rate at 1 year were found following pelvic fracture in elderly patients.

Radiologic analysis of the tibial intramedullary canal in Chinese varus knees: implications in total knee arthroplasty

Seventy-two lower limb long radiographs were reviewed with respect to mechanical and anatomic axes. A template of an intramedullary tibial guide rod was employed to determine the accuracy of the intramedullary guide in producing ideal tibial cuts (ie, 90 degrees ) and acceptable tibial cuts (ie, 90 degrees +/- 2 degrees ). The mean difference of the angle formed by the 2 axes was 1.84 degrees +/- 1.42 degrees. In our findings, 22.2% of patients would have unacceptable cuts if an intramedullary device were employed for the tibial cut during a total knee arthroplasty. A radiograph showing the whole tibia is required preoperatively to identify varus tibiae that are not suitable for the intramedullary method.

The combined use of flaps based on the subscapular vascular system for limb reconstruction

The combined use of flaps based on the subscapular vascular system for limb reconstructions has been infrequently reported. Such combinations have mainly been used for mandibular and facial reconstructions. We have used these flaps as free flaps for lower limb reconstructions in 7 patients, in 6 cases after trauma and in one after infection. A latissimus dorsi muscle or musculocutaneous flap and serratus anterior muscle flap were used together in 4 cases, and a latissimus dorsi muscle flap and parascapular flap in 3 cases. All cases healed satisfactorily. The indications for the combined use of these flaps are to resurface two separate defects simultaneously or to resurface very large defects. The anatomy of the subscapular vascular system allows the combined use of two or more flaps. It has the advantage of requiring anastomosis of one vascular pedicle only. Such combined flaps are particularly suitable for resurfacing defects wider than their length in relation to the long axis of the limb.

Fracture of the tibial tubercle in the adolescent

We have reviewed 16 patients with avulsion fractures of the tibial tubercle, mostly boys who sustained left-sided injuries during sport. Two-thirds had type I or II injuries and were treated conservatively. Fractures involving the knee joint (type III) had internal fixation. The final results were good except for minor complications such as a prominent and uncomfortable tibial tubercle.

The relationship between income, education and hypertension

A sample survey was conducted in South Carolina to determine how income and education relate to hypertension, independently of age, race and sex. The results indicated that there was a significant inverse relationship between income and hypertension for Whites (P < 0·0001), but not for Blacks. There was also a statistically significant inverse relationship between education and hypertension for Whites (P < 0·0001) and for Blacks (P < 0·001).