Does the Watson-Jones or Modified Smith-Petersen Approach Provide Superior Exposure for Femoral Neck Fracture Fixation?

BACKGROUND: A well-reduced femoral neck fracture is more likely to heal than a poorly reduced one, and increasing the quality of the surgical exposure makes it easier to achieve anatomic fracture reduction. Two open approaches are in common use for femoral neck fractures, the modified Smith-Petersen and Watson-Jones; however, to our knowledge, the quality of exposure of the femoral neck exposure provided by each approach has not been investigated. QUESTIONS/PURPOSES: (1) What is the respective area of exposed femoral neck afforded by the Watson-Jones and modified Smith-Petersen approaches? (2) Is there a difference in the ability to visualize and/or palpate important anatomic landmarks provided by the Watson-Jones and modified Smith-Petersen approaches? METHODS: Ten fresh-frozen human pelvi underwent both modified Smith-Petersen (utilizing the caudal extent of the standard Smith-Petersen interval distal to the anterosuperior iliac spine and parallel to the palpable interval between the tensor fascia lata and the sartorius) and Watson-Jones approaches. Dissections were performed by three fellowship-trained orthopaedic traumatologists with extensive experience in both approaches. Exposure (in cm) was quantified with calibrated digital photographs and specialized software. Modified Smith-Petersen approaches were analyzed before and after rectus femoris tenotomy. The ability to visualize and palpate seven clinically relevant anatomic structures (the labrum, femoral head, subcapital femoral neck, basicervical femoral neck, greater trochanter, lesser trochanter, and medial femoral neck) was also recorded. The quantified area of the exposed proximal femur was utilized to compare which approach afforded the largest field of view of the femoral neck and articular surface for assessment of femoral neck fracture and associated femoral head injury. The ability to visualize and palpate surrounding structures was assessed so that we could better understand which approach afforded the ability to assess structures that are relevant to femoral neck fracture reduction and fixation. RESULTS: After controlling for age, body mass index, height, and sex, we found the modified Smith-Petersen approach provided a mean of 2.36 cm (95% confidence interval [CI], 0.45-4.28 cm; p = 0.015) additional exposure without rectus femoris tenotomy (p = 0.015) and 3.33 cm (95% CI, 1.42-5.24 cm; p = 0.001) additional exposure with a tenotomy compared with the Watson-Jones approach. The labrum, femoral head, subcapital femoral neck, basicervical femoral neck, and greater trochanter were reliably visible and palpable in both approaches. The lesser trochanter was palpable in all of the modified Smith-Petersen and none of the Watson-Jones approaches (p < 0.001). All modified Smith-Petersen approaches (10 of 10) provided visualization and palpation of the medial femoral neck, whereas visualization of the medial femoral neck was only possible in one of 10 Watson-Jones approaches (p < 0.001) and palpation was possible in eight of 10 Watson-Jones versus all 10 modified Smith-Petersen approaches (p = 0.470). CONCLUSIONS: In the hands of surgeons experienced with both surgical approaches to the femoral neck, the modified Smith-Petersen approach, with or without rectus femoris tenotomy, provides superior exposure of the femoral neck and articular surface as well as visualization and palpation of clinically relevant proximal femoral anatomic landmarks compared with the Watson-Jones approach. CLINICAL RELEVANCE: Open reduction and internal fixation of a femoral neck fracture is typically performed in a young patient (< 60 years old) with the objective of obtaining anatomic reduction that would not be possible by closed manipulation, thus enhancing healing potential. In the hands of surgeons experienced in both approaches, the modified Smith-Petersen approach offers improved direct access for reduction and fixation. Higher quality reductions and fixation are expected to translate to improved healing potential and outcomes. Although our experimental results are promising, further clinical studies are needed to verify if this larger exposure area imparts increased quality of reduction, healing, and improved outcomes compared with other approaches. The learning curve for the exposure is unclear, but the approach has broad applications and is frequently used in other subspecialties such as for direct anterior THA and pediatric septic hip drainage. Surgeons treating femoral neck fractures with open reduction and fixation should familiarize themselves with the modified Smith-Petersen approach.

Two Genetic Variants Associated with Plantar Fascial Disorders.

Plantar fascial disorder is comprised of plantar fasciitis and plantar fibromatosis. Plantar fasciitis is the most common cause of heel pain, especially for athletes involved in running and jumping sports. Plantar fibromatosis is a rare fibrous hyperproliferation of the deep connective tissue of the foot. To identify genetic loci associated with plantar fascial disorders, a genome-wide association screen was performed using publically available data from the Research Program in Genes, Environment and Health including 21,624 cases of plantar fascial disorders and 80,879 controls. One indel (chr5:118704153:D) and one SNP (rs62051384) showed an association with plantar fascial disorders at genome-wide significance (p<5×10-8) with small effects (odds ratios=0.93 and 1.07 per allele, respectively). The indel chr5:118704153:D is located within TNFAIP8 (encodes a protein induced by TNF alpha) and rs62051384 is located within WWP2 (which is involved in proteasomal degradation). These DNA variants may be informative in explaining why some individuals are at higher risk for plantar fascial disorders than others.

Two Genetic Loci associated with Medial Collateral Ligament Injury.

Medial collateral ligament (MCL) injuries are a common knee injury, especially in competitive athletes. Identifying genetic loci associated with MCL injury could shed light on its etiology. A genome-wide association screen was performed using data from the Research Program in Genes, Environment and Health (RPGEH) including 1 572 cases of MCL injury and 100 931 controls. 2 SNPs (rs80351309 and rs6083471) showed an association with MCL injury at genome-wide significance (p<5×10-8) with moderate effects (odds ratios=2.12 and 1.57, respectively). For rs80351309, the genotypes were imputed with only moderate accuracy, so this SNP should be viewed with caution until its association with MCL injury can be validated. The SNPs rs80351309 and rs6083471 show a statistically significant association with MCL injury. It will be important to replicate this finding in future studies.

A Genetic Marker Associated with Shoulder Dislocation.

Shoulder dislocations are common shoulder injuries associated with athletic activity in contact sports, such as football, rugby, wrestling, and hockey. Identifying genetic loci associated with shoulder dislocation could shed light on underlying mechanisms for injury and identify predictive genetic markers. To identify DNA polymorphisms associated with shoulder dislocation, a genome-wide association screen was performed using publically available data from the Research Program in Genes, Environment and Health including 662 cases of shoulder dislocation and 82 602 controls from the European ancestry group. rs12913965 showed an association with shoulder dislocation at genome-wide significance (p=9.7×10-9; odds ratio=1.6) from the European ancestry group. Individuals carrying one copy of the risk allele (T) at rs12913965 showed a 69% increased risk for shoulder dislocation in our cohort. rs12913965 is located within an intron of the TICRR gene, which encodes TOPBP1 interacting checkpoint and replication regulator involved in the cell cycle. rs12913965 is also associated with changes in expression of the ISG20 gene, which encodes an antiviral nuclease induced by interferons. This genetic marker may one day be used to identify athletes with a higher genetic risk for shoulder dislocation. It will be important to replicate this finding in future studies.

Prospective Analysis of Simulated Pneumatic Tourniquet Use and Oedema Following Axillary Lymph Node Dissection.

Background: Tourniquet use during upper extremity surgery in patients with a history of axillary lymph node dissection (ALND) remains controversial due to the perceived but unproven risk of lymphoedema. We prospectively evaluated upper extremity swelling in patients with a history of unilateral ALND using a standardised tourniquet model. Methods: A tourniquet was applied to the upper arm bilaterally, with the unaffected side serving as an internal control. Each arm was subsequently held in an elevated position to reduce swelling. Hand volume was measured using an aqueous volumeter. Results: The patients' ALND arms experienced slightly greater increases in volume following tourniquet application compared to their healthy control arms. However, this amount of oedema was temporary and reversible, as both arms experienced spontaneous resolution of swelling with no significant difference in residual hand volume at the conclusion of the study. Conclusions: Tourniquet use may be safe in patients with a history of ALND. Further investigation is needed to verify this in a surgical setting. Level of Evidence: Level II (Therapeutic).

Patient-level patterns in daily prescribed opioid dosage in single level lumbar fusion are associated with postoperative opioid dosage and adverse events: a retrospective analysis of claims data.

BACKGROUND: Patients undergoing lumbar spine surgery have high rates of preoperative opioid use, which is associated with inferior outcomes and higher risks for opioid dependency postoperatively. PURPOSE: Determine whether there are identifiable subgroups of patients that follow distinct patterns in pre- and postoperative opioid dosing. Examine how preoperative patterns in opioid dosing relate to postoperative opioid patterns, opioid cessation, and the risk for adverse events. STUDY DESIGN/SETTING: Retrospective analysis of an administrative claims database (MeritiveTM Marketscan® Research Databases 2007-2015). PATIENT SAMPLE: The 9,768 patients undergoing primary single level lumbar fusion. OUTCOME MEASURES: Primary: daily morphine milligram equivalent (MME) opioid dosing calculated from prescriptions dispensed for 1 year before and after surgery; secondary: 90-day all-cause readmission and complications, 90-day acute postoperative pain, 90-day and 1-year reoperation, surgical costs, length of stay, and discharge disposition. METHODS: Distinct patient subgroups defined by patterns of daily MME pre- and postoperatively were identified via group-based trajectory modeling. Associations between these groups and outcomes were assessed with multivariable logistic regression with risk adjustment for patient and surgical factors. RESULTS: Among primary single level lumbar fusion patients, 59.5% filled an opioid prescription in the 3 months preceding surgery, whereas 40.5% were opioid naïve (Naïve). Five distinct subgroups of daily MME were identified among those filling opioids preoperatively: (1) Naïve to 3m (21.2% of patients): no opioids until 3 months preoperatively, escalating to 15 MME/day; (2) Low to 3m (11.4%): very low or as needed dose until 3 months preoperatively, escalating to 15 MME/day; (3) 6m Rise (6.9%): no opioids until 6 months preoperatively, escalating to >30 MME/day; (4) Medium (9.8%): increased linearly from 10 to 25 MME/day across the year before surgery; (5) High (10.0%): increased linearly from 60 to >80 MME/day across the year before surgery. These five preoperative opioid groups were related to postoperative opioids filled in a dose-response manner. The two preoperative patient groups with chronic Medium to High-dose opioid dosing were associated with increased adverse events, including all-cause readmission, reoperation, and pneumonia, whereas a low baseline group with a large, earlier preoperative rise in opioid dosing (6m Rise) had increased encounters for acute postoperative pain. Postoperatively, only 9.5% of patients did not fill an opioid prescription. Five distinct postoperative subgroups were identified based on their patterns in daily MME: Two groups ceased filling opioids within the year following surgery (33.6% of patients), and three groups declined in opioid dosage following surgery but plateaued at low (0-5 MME/day, 29.1%), medium (10-15 MME/day, 12.0%), or high (70-75 MME/day), 13.1%) doses by 1 year. Patients within the higher preoperative opioid groups were more likely to belong to the postoperative groups that were unable to cease filling opioids. CONCLUSIONS: Identification of a patient's preoperative time trend in daily opioid use may provide significant prognostic value and help guide pain management and risk reduction efforts. LEVEL OF EVIDENCE: III.

The effect of long-term alendronate treatment on cortical thickness of the proximal femur.

BACKGROUND: One of the radiographic hallmarks in patients with atypical femoral insufficiency fractures after prolonged bisphosphonate treatment is generalized cortical hypertrophy. Whether cortical thickening in the proximal femur is caused by long-term alendronate therapy, however, remains unknown. QUESTIONS/PURPOSES: We asked whether long-term alendronate use of 5 years or more results in progressive thickening of the subtrochanteric femoral cortices. PATIENTS AND METHODS: We retrospectively evaluated changes in cortical thickness and cortical thickness ratio (ratio of cortical to femoral shaft diameter) at the subtrochanteric region of the proximal femur in baseline and latest hip dual-energy xray absorptiometry (DXA) scans of 131 patients. The mean followup was 7.3 years. Patients were divided into two groups: control (no history of alendronate, 45 patients) and alendronate (history of alendronate ≥ 5 years, 86 patients). We determined cortical thickness and cortical thickness ratio at 3.5 and 4.0 cm below the tip of the greater trochanter, representing the subtrochanteric region. RESULTS: After a minimum of 5 years followup, mean cortical thickness decreased approximately 3% in the alendronate and control groups. The cortical thickness at the subtrochanteric femoral region changed less than 1 mm in greater than 90% of the patients with long-term alendronate treatment. We observed no differences in mean changes of cortical thickness and percent changes of cortical thickness between the two groups. CONCLUSIONS: Long-term alendronate treatment did not appear to cause thickened femoral cortices within the detection limits of our method. This finding contrasts with the notion that long-term alendronate treatment leads to generalized cortical thickening.

A fracture does not adversely affect bone mineral density responses after teriparatide treatment.

BACKGROUND: Fracture leads to local and systemic catabolic physiologic changes. As teriparatide is an agent used to treat osteoporosis in patients with fragility fractures, it is unclear whether teriparatide treatment alters bone mineral density (BMD) and bone markers when given to patients with fractures. QUESTIONS/PURPOSES: We asked whether BMD and bone marker responses would be blunted in patients with fractures placed on teriparatide after fracture compared with patients without fractures on teriparatide. PATIENTS AND METHODS: We retrospectively collected data from 141 patients treated with teriparatide for osteoporosis. Seventy-seven patients received teriparatide after fractures (fracture group), whereas 64 were treated for other indications (nonfracture group). We determined BMD at the lumbar spine and at the proximal femur before and 12 and 24 months posttreatment. Bone markers (urine N-telopeptide [urine NTX], bone-specific alkaline phosphatase [BALP]) were measured at baseline and 3, 12, and 24 months posttreatment. RESULTS: Mean lumbar spine and hip BMDs at last followup increased from baseline with no differences between groups to approximately 9% and 4% at 24 months, respectively. Both bone markers increased from baseline in the nonfracture group, peaking at 12 months. For the fracture group, only urine NTX increased at 3 and 12 months posttreatment. Although the peak levels of both bone markers in the nonfracture group were greater, there was no difference between the two groups. CONCLUSIONS: Fracture does not have a negative effect on the BMD and bone marker responses to teriparatide treatment. Clinicians should anticipate comparable BMD responses when treating patients with teriparatide for osteoporotic fractures and for other indications. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Agreement and Reliability of Lateral Patellar Tilt and Displacement following Total Knee Arthroplasty with Patellar Resurfacing.

Patellar position and alignment may be measured on routine axial radiographs by various techniques; however, the agreement and reliability of such measurements with a resurfaced patella remain unknown. This study evaluated the range and reliability of lateral patellar tilt and lateral patellar displacement following total knee arthroplasty (TKA) with a resurfaced patella among three observers on 45° Merchant view in 139 TKAs. Intraclass correlation coefficient (ICCs) were used to evaluate intraobserver agreement (IOA) and inter-rater reliability (IRR). IRR was high between each of the observers for lateral patellar tilt (ICC = 0.8) and lateral patellar displacement (ICC = 0.87). IOA was also high upon repeat measurement for the same observer for lateral patellar tilt (ICC ≥ 0.90) and lateral patellar displacement (ICC ≥ 0.86). Therefore, lateral patellar tilt and lateral patellar displacement are reproducible measurements of patellar position on a Merchant axial radiograph following a well-functioning TKA with a resurfaced patella.

Use of Navigation-Enhanced Instrumentation to Mitigate Surgical Outliers During Total Knee Arthroplasty.

Computer-assisted orthopedic surgery improves mechanical alignment and the accuracy of surgical cuts in the context of total knee arthroplasty (TKA). A simplified, navigation-enhanced instrumentation system was assessed to determine whether the same effects could be achieved with a less intrusive system. Two cohorts of surgeons (experienced and trainees) performed a series of TKA cuts using models with and without navigation-enhanced instrumentation. The accuracy of each system was determined via the rate of outliers, measured as any cut that deviated from the planned cut by more than 2° or 2 mm. The effect of experience level was limited, with only the outlier rate for tibial varus or valgus measurement showing a significant difference between user groups with conventional instrumentation (P=.004). The use of navigation-enhanced instrumentation significantly reduced the total outlier rate compared with conventional instrumentation from 35% to 4% for experienced users (P<.001) and from 34% to 10% for trainees (P<.001). These results suggest that navigation-enhanced instrumentation is a viable alternative to conventional instrumentation to reduce outlier rates and improve cut accuracy. This trial also showed that additional experience may not correlate with improved surgical accuracy. Outliers may not reflect individual surgical ability as much as limitations of the instrumentation or other unidentified factors. [Orthopedics. 2021;44(1):54-57.].

Cervical epidural steroid injections: incidence and determinants of subsequent surgery.

BACKGROUND CONTEXT: Cervical epidural steroid injections (CESIs) are sometimes used in the management of cervical radicular pain in order to delay or avoid surgery. However, the rate and determinants of surgery following CESIs remain uncertain. PURPOSE: This study sought to determine: (1) the proportion of patients having surgery following CESI, and (2) the timing of and factors associated with subsequent surgery. STUDY DESIGN: Retrospective analysis of a large, national administrative claims database. PATIENT SAMPLE: The study included 192,777 CESI patients (age 50.9±11.3 years, 55.2% female) who underwent CESI for imaging-based diagnoses of cervical disc herniation or stenosis, a clinical diagnosis of radiculopathy, or a combination thereof. OUTCOME MEASURES: The primary outcome was the time from index CESI to surgery. METHODS: Inclusion criteria were CESI for cervical disc herniation, stenosis, or radiculopathy, age ≥18, and active enrollment for 1 year before CESI to screen for exclusions. Patients were followed until they underwent cervical surgery, or their enrollment lapsed. Rates of surgery were assessed with Kaplan-Meier survival curves and 99% confidence intervals. Factors associated with subsequent surgery were assessed with multivariable Cox proportional hazard models. RESULTS: Within 6 months of CESI, 11.2% of patients underwent surgery, increasing to 14.5% by 1 year and 22.3% by 5 years. Male patients and those aged 35 to 54 had an increased likelihood of subsequent surgery. Patients with radiculopathy were less likely to undergo surgery following CESI than those with stenosis or herniation, while patients with multiple diagnoses were more likely. Patients with comorbidities including CHF, other cardiac comorbidities or chronic pain were less likely to undergo surgery, as were patients in the northeast US region. Some 33.5% of patients underwent >1 CESI, with 84.6% of these occurring within 1 year. Additional injections were associated with reduced rates of subsequent surgery. CONCLUSIONS: Following CESI, over one in five patients underwent surgery within 5 years. Multiple patient-specific risk factors for subsequent surgery were identified, and patients undergoing repeated injections were at lower risk. Determining which patients may progress to surgery can be used to improve resource utilization and to inform shared decision-making.

A Structured Review Instrument Improves the Quality of Orthopaedic Journal Club.

OBJECTIVE: We asked the following questions: 1. Does the use of an structured review instrument (SRI) at journal club increase presentation quality, as measured objectively by a standardized evaluation rubric? 2. Does SRI use increase the time required to prepare for journal club? 3. Does SRI use positively impact presenter perceptions about confidence while presenting, satisfaction, and journal club effectiveness, as measured by postparticipation surveys? DESIGN: A prospective study was designed in which a grading rubric was developed to evaluate journal club presentations. The rubric was applied to 24 presentations at journal clubs prior to introduction of the SRI. An SRI was developed and distributed to journal club participants, who were instructed to use it to prepare for journal club. The grading rubric was then used to assess 25 post-SRI presentations and scores were compared between the pre- and post-SRI groups. Presentations occurred at either trauma, pediatrics, or spine subspecialty journal clubs. Participants were also surveyed regarding time requirements for preparation, perceptions of confidence while presenting, satisfaction, and perceptions of overall club effectiveness. SETTING: A single academic center with an orthopaedic surgery residency program. PARTICIPANTS: Resident physicians in the department of orthopaedic surgery. RESULTS: Mean presentation scores increased from 14.0 ± 5.9 (mean ± standard deviation) to 24.4 ± 5.2 after introduction of the SRI (p < 0.001). Preparation time decreased from a mean of 47 minutes to 40 minutes after SRI introduction (p = 0.22). Perceptions of confidence, satisfaction, and club effectiveness among trainees trended toward more positive responses after SRI introduction (confidence: 63% positive responses pre-SRI vs 72% post-SRI, p = 0.73; satisfaction: 64% vs 91%, p = 0.18; effectiveness: 64% vs 91%, p = 0.19). CONCLUSIONS: The use of a structured review instrument to guide presentations at orthopaedic journal club increased presentation quality, and there was no difference in preparation time. There were trends toward improved presenter confidence, satisfaction, and perception of journal club effectiveness. SRI utilization at orthopaedic journal club may be an effective method for increasing the quality of journal club presentations. Future work should examine the relationship between presentation quality and overall club effectiveness.

The Relationship Between Lumbar Lateral Listhesis and Radiculopathy in Adult Scoliosis.

STUDY DESIGN: Retrospective review and prospective validation study. OBJECTIVE: To develop a classification system of lumbar lateral listhesis that suggests different likelihoods of having radiculopathy in adult scoliosis. SUMMARY OF BACKGROUND DATA: The association of lumbar lateral listhesis with radiculopathy remains uncertain. METHODS: A retrospective cohort of patients with adult scoliosis enrolled from 2011 to 2015 was studied to develop a classification system of lateral listhesis that can stratify the likelihood of having radiculopathy. Four radiological aspects of lateral listhesis, including Nash and Moe vertebral rotation, L4-L5 lateral listhesis, the number of consecutive listheses, and the presence of a contralateral lateral listhesis at the thoracolumbar junction above a caudal listhesis, were evaluated on radiographs. Their associations with the presence of radicular leg pain were evaluated using multivariable logistic regression. The classification system of lateral listhesis was thus developed using the most influential radiological factors and then validated in a prospective cohort from 2016 to 2017. RESULTS: The retrospective cohort included 189 patients. Vertebral rotation is more than or equal to grade 2 (odds ratio [OR] = 9.45, 95% confidence interval [CI]: 4.07-25.14) and L4-5 listhesis (OR = 4.56, 95%CI: 1.85-12.35) were the two most influential listhesis factors associated with radiculopathy. The classification system of lateral listhesis was thus built based on the combinations of their respective presence: Type 0, 1, 2, 3 were defined as not having listhesis at all, none of the two factors present, one of the two presents, and both present, respectively. This classification significantly stratified the probability of radiculopathy, in both the retrospective cohort (0%, 6.4%, 33.8%, and 68.4% in Type 0, 1, 2, and 3, respectively; P < 0.001) and a prospective cohort of 105 patients (0%, 16.7%, 46.9%, and 72.7%; P < 0.001). CONCLUSION: Lumbar lateral listhesis is associated with the presence of radiculopathy in adult scoliosis. Types 2 and 3 lateral listhesis on radiographs may alert surgeons treating patients with spinal deformity. LEVEL OF EVIDENCE: 2.

Improved biomechanics of two alternative kyphoplasty cementation methods limit vertebral recollapse.

The clinical efficacy of vertebral cement augmentation for compression fractures (VCFs) remains undetermined. Recent studies have shown that refracture and progression of deformity may occur after augmentation with significant clinical consequences. Vertebral body height loss following kyphoplasty has also been observed with cyclic loading. We hypothesized that height loss is partly due to lack of cement fill past the margin of cancellous bone created by balloon expansion with subsequent failure under load. The biomechanical characteristics of two alternative cementation techniques were compared to standard kyphoplasty in cyclically loaded cadaveric VCF constructs. Sectioned osteoporotic thoracolumbar cadaveric spines were compressed to 75% of anterior vertebral height. Specimens were then allocated to standard kyphoplasty, balloon pressurization (BP), with reinflation of the balloon after 50% cement injection, or endplate post (EP), with perforation of the cavity rim using an articulating curette prior to injection. Following cementation, each specimen was preconditioned and loaded over 100,000 cycles. All techniques improved vertebral height (p's < 0.005). The EP and BP techniques provided greater cement fill than the standard technique (p's ≤ 0.01). Normalized vertebral height loss following 100,000 cycles was reduced with the EP technique versus standard kyphoplasty (p < 0.04). Height loss was inversely correlated with cement fill (p < 0.03). No vertebral recollapse occurred with the EP technique in blinded radiographic analysis. Statement of clinical significance: The EP technique demonstrated improved biomechanical characteristics versus the standard technique in cadaveric osteoporotic VCF constructs with decreased recollapse following cementation. This technique may have increased efficacy in cases when kyphoplasty more substantially improves vertebral body height. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:3225-3230, 2018.

Incidence and Risk Factors for Postoperative Hypothermia After Orthopaedic Surgery.

INTRODUCTION: Postoperative hypothermia is a common complication of orthopaedic surgery associated with increased morbidity. We identified the incidence and risk factors for postoperative hypothermia across orthopaedic surgical procedures. METHODS: A total of 3,822 procedures were reviewed. Hypothermia was defined as temperature <36.0°C. Incidences were calculated and associated risk factors were evaluated by mixed-effects regression analyses. RESULTS: Hypothermia was observed in 72.5% of patients intraoperatively and 8.3% postoperatively. Risk factors for postoperative hypothermia included intraoperative hypothermia (odds ratio [OR], 2.72), lower preoperative temperature (OR, 1.46), female sex (OR, 1.42), lower body mass index (OR, 1.06 per kg/m), older age (OR, 1.02 per year), adult reconstruction by specialty (OR, 4.06), and hip and pelvis procedures by anatomic region (OR, 8.76). DISCUSSION: Intraoperative and postoperative hypothermia are common in patients who have undergone orthopaedic surgery. The high-risk groups identified in this study warrant increased attention and should be targets for interventions to prevent hypothermia and limit morbidity. LEVEL OF EVIDENCE: Level IV, prognostic study.

Selective Anterior Lumbar Interbody Fusion for Low Back Pain Associated With Degenerative Disc Disease Versus Nonsurgical Management.

STUDY DESIGN: This is a retrospective cohort study. OBJECTIVE: To evaluate the long-term outcomes of selective one- to two-level anterior lumbar interbody fusions (ALIFs) in the lower lumbar spine versus continued nonsurgical management. SUMMARY OF BACKGROUND DATA: Low back pain associated with lumbar intervertebral disc degeneration is common with substantial economic impact, yet treatment remains controversial. Surgical fusion has previously provided mixed results with limited durable improvement of pain and function. METHODS: Seventy-five patients with one or two levels of symptomatic Pfirrmann grades 3 to 5 disc degeneration from L3-S1 were identified. All patients had failed at least 6 months of nonsurgical treatment. Forty-two patients underwent one- or two-level ALIFs; 33 continued multimodal nonsurgical care. Patients were evaluated radiographically and the visual analog pain scale (VAS), Oswestry Disability Index (ODI), EuroQol five dimensions (EQ-5D), and Patient-Reported Outcomes Measurement Information System scores for pain interference, pain intensity, and anxiety. As-treated analysis was performed to evaluate outcomes at a mean follow-up of 7.4 years (range: 2.5-12). RESULTS: There were no differences in pretreatment demographics or nonsurgical therapy utilization between study arms. At final follow-up, the surgical arm demonstrated lower VAS, ODI, EQ-5D, and Patient-Reported Outcomes Measurement Information System pain intensity scores versus the nonsurgical arm. VAS and ODI scores improved 52.3% and 51.1% in the surgical arm, respectively, versus 15.8% and -0.8% in the nonsurgical arm. Single-level fusions demonstrated improved outcomes versus two-level fusions. The pseudarthrosis rate was 6.5%, with one patient undergoing reoperation. Asymptomatic adjacent segment degeneration was identified in 11.9% of patients. CONCLUSION: Selective ALIF limited to one or two levels in the lower lumbar spine provided improved pain and function when compared with continued nonsurgical care. ALIF may be a safe and effective treatment for low back pain associated with disc degeneration in select patients who fail nonsurgical management. LEVEL OF EVIDENCE: 3.

Surgery for Refractory Coccygodynia: Operative Versus Nonoperative Treatment.

STUDY DESIGN: This is a retrospective cohort study. OBJECTIVE: To evaluate the long-term outcomes for patients with refractory coccygodynia treated with coccygectomy compared to a nonsurgical regimen of sitting aids, physical therapy, medications, and injections. SUMMARY OF BACKGROUND DATA: The surgical treatment of coccygodynia remains controversial. To date, there has only been one small comparative study of surgical versus nonsurgical treatment. METHODS: From 2004 to 2014, 109 patients presenting with coccygodynia were treated with either total coccygectomy or a nonsurgical course of sitting aids, physical therapy, anti-inflammatory medications, and injections. All had at least 2 years of symptoms before surgery. The patient principally made the treatment decision, counseled by the treating physician. Before surgery, all subjects underwent at least 2 years of conservative treatment and three-dimensional imaging (computed tomography and/or magnetic resonance imaging). Subjects completed visual analog pain scales, EuroQol five-dimension, components of the PROMIS measure, and a novel Coccygodynia Disability Index evaluation. Work status, complications, and satisfaction were recorded. RESULTS: A total of 61 patients received nonsurgical care; eight declined participation and five could not be located. Forty-eight patients underwent total coccygectomy; three declined participation and five could not be located. At an average 4.8 years of follow-up (range: 2-9), the nonsurgical visual analog pain scales was 5 and the surgical 2 (P = 0.001); 79% of surgically treated patients were improved at 2 years versus 43% for the nonsurgical group. EuroQol five-dimension (P = 0.002), Coccygodynia Disability Index (0.01), and PROMIS Pain interference scores (0.02) were also significantly improved in the surgical group. Eleven surgical patients (26%) had complications, all wound related with successful resolution; seven treated with dressing changes and four with surgical debridement. CONCLUSION: Total coccygectomy is a safe and effective surgical treatment of coccygodynia refractory to nonoperative care. Patient-reported outcome measures were improved after surgery compared with nonsurgical management. Postoperative wound care remains a concern. LEVEL OF EVIDENCE: 4.

Genome-wide association study identifies a locus associated with rotator cuff injury.

Rotator cuff tears are common, especially in the fifth and sixth decades of life, but can also occur in the competitive athlete. Genetic differences may contribute to overall injury risk. Identifying genetic loci associated with rotator cuff injury could shed light on the etiology of this injury. We performed a genome-wide association screen using publically available data from the Research Program in Genes, Environment and Health including 8,357 cases of rotator cuff injury and 94,622 controls. We found rs71404070 to show a genome-wide significant association with rotator cuff injury with p = 2.31x10-8 and an odds ratio of 1.25 per allele. This SNP is located next to cadherin8, which encodes a protein involved in cell adhesion. We also attempted to validate previous gene association studies that had reported a total of 18 SNPs showing a significant association with rotator cuff injury. However, none of the 18 SNPs were validated in our dataset. rs71404070 may be informative in explaining why some individuals are more susceptible to rotator cuff injury than others.

Two genetic loci associated with ankle injury.

Ankle injuries, including sprains, strains and other joint derangements and instability, are common, especially for athletes involved in indoor court or jumping sports. Identifying genetic loci associated with these ankle injuries could shed light on their etiologies. A genome-wide association screen was performed using publicly available data from the Research Program in Genes, Environment and Health (RPGEH) including 1,694 cases of ankle injury and 97,646 controls. An indel (chr21:47156779:D) that lies close to a collagen gene, COL18A1, showed an association with ankle injury at genome-wide significance (p = 3.8x10-8; OR = 1.99; 95% CI = 1.75-2.23). A second DNA variant (rs13286037 on chromosome 9) that lies within an intron of the transcription factor gene NFIB showed an association that was nearly genome-wide significant (p = 5.1x10-8; OR = 1.63; 95% CI = 1.46-1.80). The ACTN3 R577X mutation was previously reported to show an association with acute ankle sprains, but did not show an association in this cohort. This study is the first genome-wide screen for ankle injury that yields insights regarding the genetic etiology of ankle injuries and provides DNA markers with the potential to inform athletes about their genetic risk for ankle injury.

Genome-wide association screens for Achilles tendon and ACL tears and tendinopathy.

Achilles tendinopathy or rupture and anterior cruciate ligament (ACL) rupture are substantial injuries affecting athletes, associated with delayed recovery or inability to return to competition. To identify genetic markers that might be used to predict risk for these injuries, we performed genome-wide association screens for these injuries using data from the Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort consisting of 102,979 individuals. We did not find any single nucleotide polymorphisms (SNPs) associated with either of these injuries with a p-value that was genome-wide significant (p<5x10-8). We found, however, four and three polymorphisms with p-values that were borderline significant (p<10-6) for Achilles tendon injury and ACL rupture, respectively. We then tested SNPs previously reported to be associated with either Achilles tendon injury or ACL rupture. None showed an association in our cohort with a false discovery rate of less than 5%. We obtained, however, moderate to weak evidence for replication in one case; specifically, rs4919510 in MIR608 had a p-value of 5.1x10-3 for association with Achilles tendon injury, corresponding to a 7% chance of false replication. Finally, we tested 2855 SNPs in 90 candidate genes for musculoskeletal injury, but did not find any that showed a significant association below a false discovery rate of 5%. We provide data containing summary statistics for the entire genome, which will be useful for future genetic studies on these injuries.