Anatomic and Biomechanical Evaluation of Ulnar Tunnel Position in Medial Ulnar Collateral Ligament Reconstruction.

BACKGROUND: Although numerous techniques of reconstruction of the medial ulnar collateral ligament (mUCL) have been described, limited evidence exists on the biomechanical implication of changing the ulnar tunnel position despite the fact that more recent literature has clarified that the ulnar footprint extends more distally than was appreciated in the past. PURPOSE: To evaluate the size and location of the native ulnar footprint and assess valgus stability of the medial elbow after UCL reconstruction at 3 ulnar tunnel locations. STUDY DESIGN: Controlled laboratory study. METHODS: Eighteen fresh-frozen cadaveric elbows were dissected to expose the mUCL. The anatomic footprint of the ulnar attachment of the mUCL was measured with a digitizing probe. The area of the ulnar footprint and midpoint relative to the joint line were determined. Medial elbow stability was tested with the mUCL in an intact, deficient, and reconstructed state after the docking technique, with ulnar tunnels placed at 5, 10, or 15 mm from the ulnotrochlear joint line. A 3-N·m valgus torque was applied to the elbow, and valgus rotation of the ulna was recorded via motion-tracking cameras as the elbow was cycled through a full range of motion. After kinematic testing, specimens were loaded to failure at 70° of elbow flexion. RESULTS: The mean ± SD length of the mUCL ulnar footprint was 27.4 ± 3.3 mm. The midpoint of the anatomic footprint was located between the 10- and 15-mm tunnels across all specimens at a mean 13.6 mm from the joint line. Sectioning of the mUCL increased elbow valgus rotation throughout all flexion angles and was statistically significant from 30° to 100° of flexion as compared with the intact elbow (P < .05). mUCL reconstruction at all 3 tunnel locations restored stability to near intact levels with no significant differences among the 3 ulnar tunnel locations at any flexion angle. CONCLUSION: Positioning the ulnar graft fixation site up to 15 mm from the ulnotrochlear joint line does not significantly increase valgus rotation in the elbow. CLINICAL RELEVANCE: A more distal ulnar tunnel may be a viable option to accommodate individual variation in morphology of the proximal ulna or in a revision setting.

Outpatient Total Shoulder Arthroplasty Does Not Increase the 90-Day Risk of Complications Compared With Inpatient Surgery in Prescreened Patients.

Outpatient total joint arthroplasty is becoming a more attractive option for hospitals, surgeons, and patients. In this study, the authors evaluated the safety of outpatient shoulder arthroplasty by comparing an outpatient cohort with an inpatient cohort. Ninety-day outcomes of consecutively performed elective shoulder arthroplasty cases from 2012 to 2016 were retrospectively reviewed. Patients were preoperatively assigned to outpatient or inpatient care. Primary outcomes were emergency department visits, readmissions, mortality, and surgical morbidity within 90 days of surgery. Two-tailed t tests were used to evaluate differences. Bivariate and multivariate logistic regressions were used to determine if the odds of emergency department visit, readmission, or complications were significantly different between the cohorts. There were 118 outpatient and 64 inpatient shoulder arthroplasty procedures. Mean age and American Society of Anesthesiologists score were lower in the outpatient group compared with the inpatient group-68.1 vs 72.4 years (P=.01) and 2.3 vs 2.6 (P<.01), respectively. In the multivariate logistic regression model including all arthroplasty cases, the odds of outpatient to inpatient readmission was significantly different (odds ratio, 0.181; P=.027). However, when only total shoulder arthroplasty cases were included, no difference was detected. No statistically significant difference was noted for number of emergency department visits, mortality, or surgical morbidity within 90 days of surgery in any of the models. There was 1 death in the ambulatory group at 28 days after surgery. On the basis of these findings, the authors believe that, for carefully selected patients, an outpatient shoulder arthroplasty protocol is safe when compared with inpatient protocols. [Orthopedics. 2018; 41(4):e563-e568.].

Anatomic Evaluation of the Sacroiliac Joint: A Radiographic Study with Implications for Procedures.

BACKGROUND: Sacroiliac joint (SI) pain is increasingly being recognized as a source of low back pain. Injections and percutaneous type procedures are performed to treat symptomatic joints. However, there are limited studies available assessing the anatomy of the SI joint in vivo among patients with pain. OBJECTIVES: The purpose of this study was to provide more precise information on the dimensions and orientation of the SI joint using a new technique for the radiographic evaluation of this joint. STUDY DESIGN: Observational study. SETTING: Emergency department METHODS: Three dimensional computed tomographic (CT) reconstructions of the pelvis were formatted from 100 SI joints in 50 patients who had clinically indicated abdominal/pelvic scans. These images were manipulated to evaluate the SI joint in multiple planes and measure its dimensions, area, and relationship to anatomic landmarks such as the anterior superior iliac spine (ASIS) and posterior superior iliac spine (PSIS). RESULTS: Of the 50 patients, 23 were men and 27 women. Their mean age was 47.6 years (± 18.1). The SI joint consists of a superior limb which measures 39.7 mm (± 4.8) in length, and an inferior limb which measures 54.3 mm (± 5.1), oriented at an angle of 100.1° (± 8.1) to one another. The mean area of the joint was 1276.8 mm2 (± 189.8). The horizontal distance from the ASIS to the front of the superior SI joint is 75.4 mm (± 8.4). The horizontal distance from the PSIS to the back of the superior SI joint is 43.9 mm (± 5.6). The joint stretches 7.5 mm (± 5.9) cephalad and 38.1 mm (± 6.4) caudal to the PSIS, and 35.4 mm (± 8.8) cephalad and 10.2 mm (± 11.4) caudal to the ASIS. LIMITATIONS: CT scans were performed with patients lying supine, while most SI joint procedures are performed with a patient prone. However it is doubtful that the bony anatomic landmarks would change appreciable in this largely immobile joint. These patients were seen in the emergency department for a variety of conditions related to abdominal and pelvic pain, and not exclusively for SI joint pain. CONCLUSIONS: Treatment of the SI joint by surgeons and interventionalists is hampered by the limited number of anatomic studies in the literature. Our study presents the SI joint as a 2-limbed structure, sitting from slightly above the level of the PSIS rostrally to slightly below the level of the ASIS caudally. Palpation of these landmarks may assist in directing physicians to the joint. To begin an interventional pain procedure, with a patient lying prone, this data supports tilting the x-ray image intensifier 10 degrees caudal past the vertical anteroposterior (AP) view for optimal approach of the SI joint's inferior limb. The needle entry should be about 44.1 mm (1.75 inches) caudal to the PSIS. The image intensifier should have a 12 degree left lateral oblique view for injection of the right SI joint, and a 12 degree right lateral oblique view for the left SI joint.

Prevalence of painful peroneal tubercles in the pediatric population.

Pain isolated to the lateral aspect of the heel can be difficult to diagnose, particularly in the growing child. Peroneal tendinopathy or frank tears of the peroneal tendons secondary to an enlarged peroneal tubercle has been implicated as a potential source of pain in adults. Neither the prevalence of enlarged peroneal tubercles in the pediatric population nor the number of symptomatic tubercles in children has been elucidated. We conducted a review of children who presented to our institution with foot and/or ankle pain and who underwent 3-dimensional computed tomography. Initially, a radiographic review was undertaken of all computed tomography scans to determine the prevalence of peroneal tubercles in children. The peroneal tubercles were measured and then classified according to height. The children with tubercles 3 mm or greater in height (adult mean height) underwent a more detailed chart review to evaluate for the incidence of painful tubercles. During the study period, 2,689 children were seen for foot and ankle pain, and 367 underwent a computed tomography scan during their treatment course. Of these 367 patients, 57% had a measurable peroneal tubercle, and 162 (44%) met the criteria for chart review. Only 3 adolescents (1.9%) were found to have clinical symptoms and ultimately underwent surgical excision with successful relief of symptoms. Peroneal tubercle hypertrophy appears to exist in the pediatric population; however, in contrast to adults with associated peroneal tendinopathy and tears, the children in our series had isolated painful tubercles without significant tendinopathy. The clinical examination is important in the diagnosis, and treatment by excision appears to be successful. Although a relatively rare etiology of pain, it is important that treating physicians keep this pathologic process in the differential diagnosis, because conservative management might not reduce the pain in these children.

Continuous femoral nerve blocks: varying local anesthetic delivery method (bolus versus basal) to minimize quadriceps motor block while maintaining sensory block.

BACKGROUND: Whether the method of local anesthetic administration for continuous femoral nerve blocks--basal infusion versus repeated hourly bolus doses--influences block effects remains unknown. METHODS: Bilateral femoral perineural catheters were inserted in volunteers (n = 11). Ropivacaine 0.1% was concurrently administered through both catheters: a 6-h continuous 5 ml/h basal infusion on one side and 6 hourly bolus doses on the contralateral side. The primary endpoint was the maximum voluntary isometric contraction (MVIC) of the quadriceps femoris muscle at hour 6. Secondary endpoints included quadriceps MVIC at other time points, hip adductor MVIC, and cutaneous sensation 2 cm medial to the distal quadriceps tendon in the 22 h after initiation of local anesthetic administration. RESULTS: Quadriceps MVIC for limbs receiving 0.1% ropivacaine as a basal infusion declined by a mean (SD) of 84% (19) compared with 83% (24) for those receiving 0.1% ropivacaine as repeated bolus doses between baseline and hour 6 (paired t test P = 0.91). Intrasubject comparisons (left vs. right) also reflected a lack of difference: the mean basal-bolus difference in quadriceps MVIC at hour 6 was -1.1% (95% CI -22.0-19.8%). The similarity did not reach the a priori threshold for concluding equivalence, which was the 95% CI decreasing within ± 20%. There were similar minimal differences in the secondary endpoints during local anesthetic administration. CONCLUSIONS: This study did not find evidence to support the hypothesis that varying the method of local anesthetic administration--basal infusion versus repeated bolus doses--influences continuous femoral nerve block effects to a clinically significant degree.