Is routine blood typing and screening necessary before primary total hip or knee arthroplasty in the 21st century?

BACKGROUND: Blood loss warranting transfusion is a relatively rare complication of major-joint arthroplasty procedures like total knee arthroplasty (TKA) and total hip arthroplasty (THA). Despite this rarity, pre-transfusion testing (blood typing, screening, and cross-matching) has become routine. We sought to determine if such routine testing is necessary for patients who undergo a primary TKA or THA by (1) measuring the current rate of intraoperative transfusions in primary TKA and THA patients, (2) identifying risk factors for transfusions, and (3) calculating the costs of such blood typing and screening. STUDY METHODS: We retrospectively examined the records of 992 patients who underwent primary TKA, THA, or unicompartmental knee arthroplasty (UKA) to identify patients requiring intra-operative or in-hospital postoperative transfusions. Demographic and baseline clinical and laboratory data also were collected and analyzed to identify predictors of transfusion. Cost analysis was performed. RESULTS: The rate of intraoperative transfusion was 1.7% (17/992 patients), with rates of 2.1%, 1.6%, and 0% for TKA, THA, and UKA respectively. The in-hospital transfusion rate was 10.3%, with corresponding postoperative transfusion rates of 9.1%, 12.9%, and 2%. The only baseline variable significantly linked to transfusions on multivariable analysis was preoperative hemoglobin level, with preoperative Hgb <12 g/dl predictive of transfusions in both TKA (p = .02) and THA (p = .024) patients. DISCUSSION: Our study suggests that pre-transfusion testing for all patients undergoing primary UKA, TKA or THA is unnecessary. We recommend reserving routine pre-transfusion testing for patients with preoperative hemoglobin levels below 12 g/dl.

The role of subscapularis muscle denervation in the pathogenesis of shoulder internal rotation contracture after neonatal brachial plexus palsy: a study in a rat model.

We assessed the role of subscapularis muscle denervation in the development of shoulder internal rotation contracture in neonatal brachial plexus injury. Seventeen newborn rats underwent selective denervation of the subscapular muscle. The rats were evaluated at weekly intervals to measure passive shoulder external rotation. After 4 weeks, the animals were euthanized. The subscapularis thickness was measured using 7.2T MRI axial images. The subscapularis muscle was then studied grossly, and its mass was registered. The fiber area and the area of fibrosis were measured using collagen-I inmunostained muscle sections. Significant progressive decrease in passive shoulder external rotation was noted with a mean loss of 58° at four weeks. A significant decrease in thickness and mass of the subscapularis muscles in the involved shoulders was also found with a mean loss of 69%. Subscapularis muscle fiber size decreased significantly, while the area of fibrosis remained unchanged. Our study shows that subscapularis denervation, per se, could explain shoulder contracture after neonatal brachial plexus injury, though its relevance compared to other pathogenic factors needs further investigation.

The role of muscle imbalance in the pathogenesis of shoulder contracture after neonatal brachial plexus palsy: a study in a rat model.

BACKGROUND: An internal rotation contracture of the shoulder is common after neonatal brachial plexus injuries due to subscapularis shortening and atrophy. It has been explained by 2 theories: muscle denervation and muscle imbalance between the internal and external rotators of the shoulder. The goal of this study was to test the hypothesis that muscle imbalance alone could cause subscapularis changes and shoulder contracture. MATERIALS AND METHODS: We performed selective neurectomy of the suprascapular nerve in 15 newborn rats to denervate only the supraspinatus and the infraspinatus muscles, leaving the subscapularis muscle intact. After 4 weeks, passive shoulder external rotation was measured and a 7.2-T magnetic resonance imaging scan of the shoulders was used to determine changes in the infraspinatus and subscapularis muscles. The subscapularis muscle was weighed to determine the degree of mass loss. An additional group of 10 newborn rats was evaluated to determine the sectional muscle fiber size and muscle area of fibrosis by use of images from type I collagen immunostaining. RESULTS: There was a significant decrease in passive shoulder external rotation, with a mean loss of 66°; in the thickness of the denervated infraspinatus, with a mean loss of 40%; and in the thickness and weight of the non-denervated subscapularis, with mean losses of 28% and 25%, respectively. No differences were found in subscapularis muscle fiber size and area of fibrosis between shoulders after suprascapular nerve injury. CONCLUSIONS: Our study supports the theory that shoulder muscle imbalance is a cause of shoulder contracture in patients with neonatal brachial plexus palsy.

Reports of magnetic resonance images of the hip in patients with femoroacetabular impingement: is useful information provided to the orthopedic surgeon?

OBJECTIVE: The aim of this study was twofold: (1) To evaluate the quality of radiology reports of MR imaging/arthrography (MRI/MRA) of the hip performed on symptomatic young adults with suspected femoroacetabular impingement (FAI); and (2) to assess if MRI/MRA reports provide relevant information for surgical decision-making. MATERIALS AND METHODS: We evaluated 110 MRI/MRA reports provided by 73 radiologists from 42 institutions. The images were requested preoperatively in young adults who underwent hip-preserving surgery for treatment of FAI. The quality of reports was graded using Lee's method by two independent observers. The description of seven characteristics of the hip joint was scrutinized in order to assess if the reports contained relevant information for surgical decision-making. RESULTS: The quality of reports was Grade IIA in two cases (1.8 %), IIB in six (5.5 %), III in 60 (54.5 %), and IV in 42 (38.2 %). Relevant hip characteristics for the study of FAI were reported as follows: acetabular labrum (88.1 %), cartilage characteristics (69 %), morphology of the femoral head-neck junction (34.5 %), acetabular version (6.3 %), acetabular coverage (20.9 %), soft tissues description (82.7 %), and presence of bone marrow edema (80.9 %). The vast majority (91.8 %) of the reports described five or less relevant FAI characteristics. CONCLUSIONS: Most of the radiology reports of MRI/MRA of the hip performed on symptomatic young adults with FAI were of the highest quality. However, some characteristics believed to be important for surgical decision-making in this particular group of patients were frequently not described. The inclusion of these hip joint characteristics in the radiology reports may improve the usefulness of the information provided to the orthopedic surgeon.