Roussouly classification of adult spinal deformity.

With an estimated prevalence of 68% among healthy adults without a previous diagnosis of scoliosis, adult spinal deformities are a growing concern as the population ages. Our understanding of this growing concern has been historically guided by previous studies performed on the pediatric population. Over time, different classifications have been developed with their own respective limitations. The Roussouly classification was the first classification to describe the shapes of an asymptomatic spine. It considers lumbar lordosis, pelvic incidence, and the inflection point from lumbar lordosis to thoracic kyphosis to attempt to stratify the shapes of an asymptomatic spine. This classification aims to guide treatment, provide information regarding prognosis, allow stratification for research, and be highly reproducible. Overall, the Roussouly classification is a novel way to think about sagittal malalignment, considering the patient's individual anatomy, while allowing for communication between surgeons. Additionally, it has proven to be a reliable system that provides prognostic value for clinicians and may minimize complications when a patient's sagittal alignment is optimized using this classification system.

Therapeutic TNF-alpha Delivery After CRISPR Receptor Modulation in the Intervertebral Disc.

Low back pain (LBP) ranks among the leading causes of disability worldwide and generates a tremendous socioeconomic cost. Disc degeneration, a leading contributor to LBP, can be characterized by the breakdown of the extracellular matrix of the intervertebral disc (IVD), disc height loss, and inflammation. The inflammatory cytokine TNF-α has multiple pathways and has been implicated as a primary mediator of disc degeneration. We tested our ability to regulate the multiple TNF-α inflammatory signaling pathways in vivo utilizing CRISPR receptor modulation to slow the progression of disc degeneration in rats. Sprague-Dawley rats were treated with CRISPRi-based epigenome-editing therapeutics targeting TNFR1 and showed a decrease in behavioral pain in a disc degeneration model. Surprisingly, while treatment with the vectors alone was therapeutic, TNF-α injection itself became therapeutic after TNFR1 modulation. These results suggest direct inflammatory receptor modulation, to harness beneficial inflammatory signaling pathways, as a potent strategy for treating disc degeneration.

Association of Normal vs Abnormal Meary Angle With Hindfoot Malalignment and First Metatarsal Rotation: A Short Report.

BACKGROUND: Recent work has reported a significant association between first metatarsal (M1) rotation and hindfoot alignment, with the finding of a moderate association between the calcaneal moment arm (CMA) and 2 M1 pronation angular measures: Saltzman (r = 0.641, P < .01) and Kim (r = 0.615, P < .01). The aim of the current post hoc investigation was to determine if this association is related with Meary angle. METHODS: We reanalyzed previously published data set separating patients into 2 groups: (1) those with normal Meary angle (n = 128) and (2) those with abnormal Meary angle (n = 147). Hindfoot alignment and M1 rotation were measured on weightbearing computed tomography. Statistical analyses were performed to evaluate for association between these variables among the groups. RESULTS: The correlation between CMA and M1 rotation of the entire cohort was r = 0.577 (Saltzman ankle) and r = 0.540 (Kim angle). For the subset with a normal Meary angle, this association was negligible (Saltzman and Kim angles, r = 0.194 and 0.240, respectively). Conversely, for the abnormal Meary angle subset, the association was substantial (Saltzman and Kim angles, r = 0.733 and 0.675, respectively). CONCLUSION: Patients presenting with an abnormal Meary angle and hindfoot deformity have a high likelihood of manifesting a proportionate degree of M1 rotation. LEVEL OF EVIDENCE: Level III, Retrospective Cohort Study.

Association Between Hindfoot Alignment and First Metatarsal Rotation.

BACKGROUND: The association between forefoot and hindfoot position for planus and cavus feet is fundamental to the treatment of these deformities. However, no studies have evaluated the association between hindfoot alignment and first metatarsal (M1) axial rotation. Understanding this possible relationship may help to understand the deformity and improve patient care. The purpose of this study is to determine a correlation between hindfoot alignment and metatarsal rotation as assessed by weightbearing computed tomography (WBCT). METHODS: Patients who underwent weightbearing plain radiography (WBPR) and WBCT between 2015 and 2018 were evaluated. Hindfoot alignment was measured with the calcaneal moment arm (CMA). M1 rotation was measured using the Kim and Saltzman angles. Patient subgroups were created according to the severity of valgus/varus hindfoot alignment. Statistical analyses were performed to evaluate for association between variables. RESULTS: Among the 196 patient feet included in the study, the average CMA was 6.0 ± 16.2 mm. The average Kim and Saltzman angles were 7.7 ± 12.9 degrees and 2.8 ± 13.1 degrees, respectively. The average Meary angle was 182.0 ± 11.9 degrees. A moderately strong association was found between the CMA and the Saltzman (r = 0.641, P < .01) and Kim angles (r = 0.615, P < .01). Hindfoot valgus was associated with M1 pronation and hindfoot varus with M1 supination. Additionally, inverse relationships between the Meary angle and the Saltzman (r = -0.600, P < .01) and Kim angles (r = -0.529, P < .01) were identified. CONCLUSION: In this well-defined cohort, we found substantial correlation between hindfoot alignment and M1 rotation. Hindfoot valgus was associated with M1 pronation, and hindfoot varus was associated with M1 supination. Surgeons correcting cavovarus/planovalgus deformities should be aware of this association and evaluate the need for first-ray derotation. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

A Narrow Posterior Joint Space on a False Profile Radiograph Does Not Correlate With Posterior Joint Cartilage Degeneration in Hip Preservation Patients.

PURPOSE: To evaluate whether a narrow posterior joint space (<2 mm) correlated with posterior joint cartilage degeneration in the hip preservation patient population. METHODS: A retrospective chart review of 155 consecutive hip arthroscopy cases by a single surgeon (SKA) from March 2012 to February 2013 was performed. Patients were included in the study if they had an adequate perioperative false profile radiograph and clear intraoperative arthroscopic images of the posterior hip joint. The narrowest posterior joint space (NPJS) width and the directly posterior, posterosuperior, superior, and anterosuperior joint space widths were measured on the false profile radiograph. Femoral and acetabular cartilage of the posterior hip joint were graded according to the International Cartilage Repair Society (ICRS) classification system using arthroscopic images obtained at the time of surgery. The cartilage grades of patients with <2 mm NPJS were compared with cartilage grades of patients with ≥2 mm NPJS. RESULTS: There was no difference in cartilage grading between patients with <2 mm NPJS (19 patients) and those with ≥2 mm NPJS (81 patients) (P = .905). The mean age of patients with NPJS ≥2 mm and <2 mm was 34.0 (median 31.2; interquartile range [IQR] 23.7, 42.9) and 38.7 (median 43.0; IQR 26.1, 50.9) respectively, and was not statistically different (P = .183). No correlation between cartilage grade and NPJS measurement was found (P = .374). CONCLUSION: In this predominantly cam-type femoroacetabular impingement patient cohort, our findings indicate there is no correlation between a <2 mm posterior hip joint narrowing seen on false profile radiographs and posterior hip cartilage degeneration confirmed with arthroscopy. Although posterior arthritis can be visualized on a false profile radiograph, a posterior joint space measurement <2 mm should not be interpreted as isolated posterior joint wear and should not be considered a hip arthroscopy contraindication. LEVEL OF EVIDENCE: Level IV, case series.

Leg dominance as a risk factor for femoroacetabular impingement syndrome.

One etiological factor of femoroacetabular impingement syndrome (FAIS) is high impact athletics involving deep hip flexion, axial loading and jumping during skeletal development. Previous work has established that there is physiologic asymmetry of the lower limbs regarding function, with the dominant limb being primarily responsible for propulsion and kicking while the non-dominant limb is responsible for stability and planting. The authors hypothesize that the dominant limb will be more likely to undergo hip arthroscopy for symptomatic FAIS. Four hundred and sixty-nine patients at a single surgical center who underwent primary or revision hip arthroscopy for cam-type FAIS were identified. Patients were asked to identify their dominant lower extremity, defined as the lower extremity preferred for kicking. Sixty patients who indicated bilateral leg dominance were excluded. It was assumed that with no association between limb dominance and the need for surgery, the dominant side would have surgery 50% of the time. Enrichment for surgery in the dominant limb was tested for using a one-sample test of proportions, determining whether the rate differed from 50%. The enrichment for surgery on the dominant side was 57% (95% confidence interval 52-62%) which was significantly different from the rate expected by chance (50%), P = 0.003. No other significant differences were noted between groups. Limb dominance appears to be an etiological factor in the development of cam-type FAIS. Patients are more likely to undergo arthroscopic treatment of FAIS on their dominant lower extremity, although the non-dominant lower extremity frequently develops FAIS as well.

Extracapsular local infiltration analgesia in hip arthroscopy patients: a randomized, prospective study.

Hip arthroscopy patients can experience significant post-operative pain. Many strategies to combat this pain have been explored including nerve blocks, which can be costly. An alternative option for pain management is local infiltration analgesia (LIA) which has been studied in hip and knee arthroplasty, but its ability to decrease pain in the setting of hip arthroscopy remains uncertain. A prospective randomized controlled trial of 74 patients who underwent hip arthroscopy at a single medical center was performed. Thirty-seven patients received a 20-ml extracapsular injection of 0.25% bupivacaine-epinephrine under direct arthroscopic visualization after capsular closure while 37 from the control group received no injection. Primary outcome measures were both maximum and discharge numeric rating scale (NRS) pain scores while in the post-anesthesia care unit (PACU). The LIA group had a statistically significant decrease in the maximum PACU NRS score (6.16 versus 7.35, P = 0.009), however this did not reach the level of minimal clinically important difference of 1.5. There was an insignificant difference in discharge PACU pain scores. This is the first randomized controlled trial studying extracapsular LIA in hip arthroscopy. While LIA offers an uncomplicated and low-cost approach to post-operative pain management, this specific technique did not reduce pain to a clinically significant level.

Progressive osteoarthritis during pregnancy several years following hip arthroscopy for femoroacetabular impingement.

CASE: A 28-year-old with borderline left hip dysplasia who underwent arthroscopic acetabuloplasty, femoral osteochondroplasty, and labral repair for femoroacetabular impingement. She did well for 8 years, though required arthroscopic capsulolabral adhesion release 2 years after the initial procedure. After this period of stability, she developed left hip pain during pregnancy. Radiographs demonstrated progressive osteoarthritis that lead to total hip arthroplasty at age 37. CONCLUSION: The physiologic and hormonal changes during pregnancy leading to increased ligamentous laxity may put vulnerable patients with hip dysplasia and iatrogenic instability at increased risk for progression of osteoarthritis.

Extracapsular local infiltration analgesia in hip arthroscopy: a retrospective study.

Many hip arthroscopy patients experience significant pain in the immediate postoperative period. Although peripheral nerve blocks have demonstrated efficacy in alleviating some of this pain, they come with significant costs. Local infiltration analgesia (LIA) may be a significantly cheaper and efficacious treatment modality. Although LIA has been well studied in hip and knee arthroplasty, its efficacy in hip arthroscopy is unclear. The purpose of this retrospective study is to determine the efficacy of a single extracapsular injection of bupivacaine-epinephrine during hip arthroscopy in reducing the rate of elective postoperative femoral nerve blocks. A retrospective review of 100 consecutive patients who underwent primary hip arthroscopy at a single medical center was performed. The control group consisted of 50 patients before the implementation of the current LIA protocol, whereas another 50 patients received a 20-ml extracapsular injection of 0.25% bupivacaine-epinephrine under direct arthroscopic visualization after capsular closure. In the post-anesthesia care unit (PACU), patients were offered a femoral nerve block for uncontrolled pain. The rate of femoral nerve block, and total opioid consumption, was compared between groups. The proportion of patients receiving elective femoral nerve blocks was significantly less in the LIA group (34%) as compared with the control group (56%; P = 0.027). There was no significant difference in total PACU opioid consumption between groups (P = 0.740). The decreased utilization of postoperative nerve blocks observed in the LIA group suggests that LIA may improve postoperative pain management and should be considered as a potentially cost-effective tool in pain management in hip arthroscopy patients. Level of Evidence: III.

Characterization of plantaris tendon constructs for ankle ligament reconstruction.

BACKGROUND: Many techniques have been described for lateral ligament reconstruction. One frequently overlooked autograft option is the plantaris tendon, potentially due to the paucity of data on its mechanical characteristics. This study examined the structural properties of double and quadruple plantaris tendon constructs. METHODS: Plantaris tendons were harvested from 35 fresh-frozen human cadaver specimens (mean age, 66 years [range, 43-89 years]; 17 female, 13 male). The tendon ends were sutured in a running locking technique and then woven onto a template board to create double or quadruple graft constructs with a 20-mm functional length. If additional tendon length remained, a single 40-mm specimen was isolated to provide tissue material properties. Structural properties were calculated from the results of cyclic and failure uniaxial tensile tests. RESULTS: Quadruple-strand constructs had a tensile strength of 205.8 ± 68.2 N and a stiffness of 133.1 ± 46.3 N/mm. Single strands had a tensile strength of 66.9 ± 26.3 N and a stiffness of 43.8 ± 14.7 N/mm. Material properties were similar to a prior study. CONCLUSIONS: The average maximum tensile strength for the quadrupled plantaris grafts exceeded the strength of the intact anterior talofibular ligament of 139 to 161 N; therefore, the quadruple plantaris construct may be a viable autograft for foot and ankle ligament reconstruction. CLINICAL RELEVANCE: The tensile strength of the plantaris tendon is comparable to, or stronger than, other grafts already in use and offers a donor site that may result in negligible loss of strength.