Assessing Leg Length and Offset in Anterior Total Hip Arthroplasty: Overlay Versus AP Pelvis Intraoperative Radiographic Techniques: A Retrospective Cohort Study.

INTRODUCTION: Two intraoperative radiographic techniques to determine leg length and offset during anterior total hip arthroplasty (THA) are the AP pelvis and overlay techniques. The AP pelvis method measures LLDs and offset using AP fluoroscopic images, whereas the overlay method uses printed images of the native and replaced hips. The purpose of this study was to compare these techniques regarding clinical and radiographic LLD and offset discrepancies. METHODS: Patients of a single surgeon at two hospitals from September 2017 to January 2021 were retrospectively reviewed. Clinically detectable LLD was recorded. Radiographic measurements were obtained from preoperative and postoperative radiographs. LLD was determined based on the vertical distance between the lesser trochanters and the ischial tuberosities. Total offset was measured using a combination of femoral and medial offset. The Student t-test, Fisher exact test, and Wilcoxon rank sum tests were used for statistical analysis. RESULTS: Seventy-one procedures were done using the overlay technique and 61 used for the AP pelvis technique. No significant differences were observed in mean postoperative LLD (2.66 versus 2.88 mm, P = 0.66) and mean postoperative offset discrepancy (5.37 versus 4.21 mm, P = 0.143) between the overlay versus AP pelvis groups. The mean preoperative to postoperative absolute difference in offset was less than 5 mm in both groups. Clinically detectable LLD was noted in six of 71 patients in the overlay group and one of 61 in the AP pelvis group (P = 0.123). CONCLUSION: No notable differences were observed in intraoperative leg length and offset discrepancies during direct anterior THA between the AP pelvis and overlay techniques, suggesting they are equally effective in determining LLD and offset intraoperatively. The choice of technique to use anterior THA should be based primarily on the surgeon's preference, comfort, and available resources.

Acromiohumeral cerclage in reverse total shoulder arthroplasty for recurrent instability.

BACKGROUND: Recurrent shoulder instability after reverse total shoulder arthroplasty (rTSA) presents a challenging clinical problem. A handful of cases have been reported describing stability achieved only after revision rTSA with cerclage augmentation. We describe an acromiohumeral cerclage technique, where the humeral component is fixed with a nonabsorbable, high-tensile suture tape looped through transosseous acromial drill tunnels as an augment to salvage shoulder stability. METHODS: All patients treated with acromiohumeral cerclage in rTSA for instability between November 1, 2015, and February 1, 2020, with minimum 1-year follow-up were included. Demographic information, baseline preoperative and postoperative range of motion at most recent follow-up, American Shoulder and Elbow Surgeons (ASES) shoulder scores, and visual analog scale (VAS) scores were recorded and compared. RESULTS: Ten patients, 4 female and 6 male, aged 64.3 ± 7.4 years (range, 53-77 years) with the mean postoperative follow-up of 23 months were included; 90% underwent surgery on the dominant side. Patients underwent an average of 2.1 ± 1.9 prior revisions (range, 0-7), over an average of 10.4 months (range, 0-72 months), before revision with suture cerclage augmentation was performed. All patients either had significant past shoulder history at other institutions and/or comorbidities that added significant complexity to their cases, with an average of 0.6 ± 0.9 (range, 0-3) prior other shoulder operations performed before their initial rTSA. The average decrease in VAS score among the 10 patients was 4.3 ± 2.7 (P < .05), ranging from 0 to 8 points. The average increase in ASES score was 51.3 ± 21 (P < .05), ranging from 13.3 to 69.9 points. The average increase in active forward elevation for 8 patients was 79° ± 39° (P = .0008), ranging from 40° to 160°. All patients have remained stable with well-positioned prostheses since their final operations with no recurrent dislocations or acromial complications. Two patients unable to travel for an office visit were contacted via phone and answered questions to obtain postoperative ASES and VAS scores. CONCLUSION: Acromiohumeral cerclage suture augmentation in revision rTSA may be a useful, simple surgical strategy to employ with other revision and augmentation techniques to treat cases of recurrent, chronic instability, particularly in the setting of multiple revisions.

Muscle-Nerve-Nerve Grafting Improves Facial Reanimation in Rats Following Facial Nerve Injury.

Nerve injury resulting in muscle paralysis from trauma or surgery is a major medical problem. Repair of such injuries with existing nerve grafting and reconstructive techniques often results in less than optimal outcomes. After previously demonstrating significant return of function using muscle-nerve-muscle (MNM) grafting in a rat facial nerve model, this study compares a variant of the technique, muscle-nerve-nerve (MNN) neurotization to MNM and interposition (IP) nerve grafting. Thirty male rats were randomized into four groups (1) control with no intervention, (2) repair with IP grafts, (3) MNM grafts and (4) MNN grafts. All groups had the buccal and marginal mandibular branches of the right facial nerve resected. Return of vibrissae movement, orientation, and snout symmetry was measured over 16 weeks. Functional recovery and muscle atrophy were assessed and quantified. All interventions resulted in significant improvement in vibrissae movement and orientation as compared to the control group (p < 0.05). The MNM and MNN groups had significantly less time to forward vibrissae movement as compared to controls (p < 0.05), and a large number of animals in the MNN group had coordinated vibrissae movement at 16 weeks. MNN and IP grafts retained significantly more muscle mass as compared to control (p < 0.05). Thus, MNN grafting is a promising adjuvant or alternative technique for reanimation for patients with unilateral peripheral nerve injury who are not candidates for primary neurorrhaphy.

Does contralateral knee range of motion predict postoperative knee range of motion after total knee arthroplasty?

PURPOSE: The aim of this study was to determine if contralateral knee range of motion is associated with postoperative range of motion in the operative knee after total knee arthroplasty. METHODS: Contralateral (nonoperative) knee range of motion was compared to postoperative knee range of motion after total knee arthroplasty using linear regression models in 59 patients who had undergone primary total knee arthroplasty with a minimum of 4 months postoperative follow-up data (range 4-13 months). RESULTS: A strong linear relationship was observed between contralateral knee ranges of motion of 115° or greater and postoperative knee ranges of motion after total knee arthroplasty (slope 0.93, 95% CI 0.58-1.29, P < 0.0001), with a mean difference of -7.44° (95% CI -10.3 to -4.63, P < 0.0001). However, there was no association between contralateral knee range of motion and postoperative knee range of motion when contralateral knee range of motion was less than 115°. CONCLUSION: Contralateral knee range of motion of 115° or greater correlates linearly with postoperative range of motion after total knee arthroplasty, and thus may be predictive in such cases.

Distinct neurotoxic effects of select local anesthetics on facial nerve injury and recovery.

BACKGROUND: Local anesthetic toxicity has been well-documented to cause neuronal injury, death, and dysfunction, particularly in a susceptible nerve. OBJECTIVE: To determine whether select local anesthetics affect neuron survival and/or functional recovery of an injured nerve. METHODS: This report describes 6 separate experiments that test immediate or delayed application of local anesthetics in 3 nerve injury models. Adult C57/black6 male mice underwent a facial nerve sham, transection, or crush injury. Local anesthetic or saline was applied to the facial nerve at the time of injury (immediate) or 1 day after injury (delayed). Average percent facial motoneuron (FMN) survival was evaluated four-weeks after injury. Facial nerve regeneration was estimated by observing functional recovery of eye blink reflex and vibrissae movement after facial nerve crush injury. RESULTS: FMN survival after: transection + immediate treatment with ropivacaine (54.8%), bupivacaine (63.2%), or tetracaine (66.9%) was lower than saline (85.5%) and liposomal bupivacaine (85.0%); crush + immediate treatment with bupivacaine (92.8%) was lower than saline (100.7%) and liposomal bupivacaine (99.3%); sham + delayed treatment with bupivacaine (89.9%) was lower than saline (96.6%) and lidocaine (99.5%); transection + delayed treatment with bupivacaine (67.3%) was lower than saline (78.4%) and liposomal bupivacaine (77.6%); crush + delayed treatment with bupivacaine (85.3%) was lower than saline (97.9%) and lidocaine (96.0%). The average post-operative time for mice to fully recover after: crush + immediate treatment with bupivacaine (12.83 days) was longer than saline (11.08 days) and lidocaine (10.92 days); crush + delayed treatment with bupivacaine (16.79 days) was longer than saline (12.73 days) and lidocaine (11.14 days). CONCLUSIONS: Our data demonstrate that some local anesthetics, but not all, exacerbate motoneuron death and delay functional recovery after a peripheral nerve injury. These and future results may lead to clinical strategies that decrease the risk of neural deficit following peripheral nerve blocks with local anesthetics.

Effects of the Number of Muscle-Nerve-Muscle Grafts on Rat Facial Nerve Functional Recovery.

INTRODUCTION: Facial nerve denervation can be devastating for patients. Primary neurorrhaphy and interposition (IP) nerve grafting are common reinnervation techniques. Muscle-nerve-muscle (MNM) grafting is a lesser known alternative. After previously demonstrating significant return of function using MNM grafting in a rat facial nerve model, the authors compare the use of multiple MNM nerve grafts with that of single MNM and IP nerve grafts. METHODS: Thirty-six male rats were randomized into 4 groups: (1) repair with IP grafts, (2) 1 MNM graft, (3) 3 MNM grafts, and (4) control with no intervention. All groups had the lower zygomatic, buccal, and marginal mandibular branches of the right facial nerve removed. Return of movement and snout symmetry was measured over 16 weeks. Axonal regeneration and muscle atrophy were assessed and quantified. RESULTS: All intervention groups had significantly improved movement and snout symmetry compared with control. Rats in the IP group had significantly increased axon density compared with those in the MNM groups but with smaller axonal diameter than control rats. No difference in axon density or diameter was observed between MNM groups. Use of 3 MNM grafts and IP grafts resulted in preservation of similar muscle mass compared with the control and 1-MNM groups. CONCLUSION: MNM grafting may be an alternative when other reanimation techniques are not possible. LEVEL OF EVIDENCE: NA.