John P. Salvo

PLACEMENT OF PEDICLE SCREWS IN THE THORACIC SPINE. PART I: MORPHOMETRIC ANALYSIS OF THE THORACIC VERTEBRAE

We studied the morphology of the thoracic vertebrae in the spines of seventeen human cadavera in order to define parameters that could be used as guidelines for the placement of hooks and screws in the pedicles to obtain internal fixation. We also reviewed computerized tomographic scans of nineteen thoracic spines in living patients who had no evidence of any vertebral deformity. The transverse diameter of the pedicle, which helps to determine the size of the screw, ranged from a mean (and standard deviation) of 4.5 +/- 1.2 millimeters in the fourth thoracic vertebra to a mean of 7.8 +/- 2.0 millimeters in the twelfth thoracic vertebra. The pedicles were inclined anteromedially throughout the thoracic spine, and the angle ranged from 0.3 degree toward the midline in the twelfth thoracic vertebra to 13.9 degrees in the fourth thoracic vertebra. The morphometric data revealed wide variations in the dimensions of the pedicles, demonstrating the importance of accurate preoperative imaging with transaxial computerized tomographic scans to visualize the precise osseous margins and angles of insertion of the thoracic pedicles.

Avulsion Fracture of the Ulnar Sublime Tubercle in Overhead Throwing Athletes

Background Injuries to the ulnar collateral ligament are relatively common in throwing athletes and result from either acute traumatic or repeated valgus stress to the elbow. Avulsion fracture of the sublime tubercle of the ulna is a rarely reported site of ulnar collateral ligament injury. Purpose We retrospectively reviewed our cases of ulnar collateral ligament injuries to study avulsion fractures of the sublime tubercle of the ulna. Study Design Case series. Methods Data, including radiographs and magnetic resonance imaging scans, were obtained by review of hospital and office records and by follow-up examination. Of 33 consecutive patients treated for ulnar collateral ligament injuries, 8 had avulsion fractures of the sublime tubercle of the ulna. All eight were male baseball players with dominant arm involvement, an average age of 16.9 years, and an average follow-up of 23.6 months. Results Six of eight patients had failure of nonoperative treatment and required surgical repair. Two of the six underwent ulnar collateral ligament reconstruction and four had direct repair of the sublime tubercle avulsion with bioabsorbable suture anchors. At last follow-up, all eight had returned to their preinjury level of activity. No patient had residual medial elbow pain or laxity. Conclusions Diagnosis of sublime tubercle avulsion fracture is made with history, physical examination, and radiographic studies. Magnetic resonance imaging can help identify an avulsion fracture not visible radio-graphically and can help determine whether direct repair or reconstruction is needed.

Incidence of Venous Thromboembolic Disease Following Hip Arthroscopy

Venous thromboembolic disease is a known complication of orthopedic surgery. Hip arthroscopy is a technically demanding procedure with a significant learning curve and low reported complication rate. Few reports document the incidence of venous thromboembolic disease following hip arthroscopy. Our hypothesis was that the incidence of venous thromboembolic disease following hip arthroscopy was comparable to that reported for knee arthroscopy. Eighty-one consecutive patients undergoing hip arthroscopy were retrospectively reviewed. All patients underwent standard diagnostic hip arthroscopy under traction of the operative leg against a well-padded perineal post. All procedures were performed on an outpatient basis. Three of 81 patients (3.7%) developed a clinically symptomatic venous thromboembolic disease in the postoperative period. The diagnosis was suspected clinically and confirmed with the use of a Doppler ultrasound. No patient developed symptomatic pulmonary emboli. One patient used oral contraceptives and 2 had no known risk factors for venous thromboembolic disease. All patients were successfully treated with anticoagulation. This is the first study to document multiple occurrences of venous thromboembolic disease following hip arthroscopy. This study demonstrated the incidence of symptomatic venous thromboembolic disease after hip arthroscopy to be 3.7%. Further study investigation is warranted regarding the incidence of symptomatic and asymptomatic venous thromboembolic disease following hip arthroscopy.

Adductor Longus Rupture in Professional Football Players: Acute Repair With Suture Anchors A Report of Two Cases

injury, and the best treatment for this injury is unknown. Most cases previously reported involved the distal insertion of the adductor longus tendon and have occurred most commonly in soccer. To our knowledge, rupture of the proximal origin has never been reported in a professional or amateur football athlete. We are reporting two cases of acute tear of the proximal insertion of adductor longus tendon repaired with suture anchors. The adductor longus muscle arises from the pubis near the symphysis and inserts onto the linea aspera of the femur. The muscle is narrow proximally and fans out to form a broad insertion on the femur. Chronic groin pain is a common problem for many athletes and has a wide variety of causes; the adductor muscle group is often a source of pain in these overuse syndromes. Acute injuries are much less common. To our knowledge, only one case of proximal adductor longus rupture has been reported in the literature. Several cases of rupture of the distal insertion have been reported; treatment of these lesions has ranged from nonoperative management to complete removal of the muscle. The mechanism of injury appears to be from eccentric overload when forced abduction of the lower extremity occurs during contraction of the adductor muscle group. We are reporting two cases of acute repair in professional athletes, the surgical technique, and a review of the literature.

Outcomes after hip arthroscopy in patients with workers' compensation claims.

Patients with a workers compensation claim have been shown to have inferior outcomes after various orthopedic procedures. In hip arthroscopy, good to excellent results have been shown in the athletic and prearthritic population in short-term and long-term follow-up. In the current study, the authors hypothesis was that patients with a workers compensation claim would have inferior outcomes after hip arthroscopy compared with patients without a workers compensation claim. All patients with a workers compensation claim who underwent hip arthroscopy over a 2-year period were studied. Postoperative functional outcomes were assessed with the Hip Outcome Score and modified Harris Hip Score. A cohort of 30 patients who did not have a workers compensation claim was selected for comparison. Twenty-six patients were identified who had a workers compensation claim and underwent hip arthroscopy performed by a single surgeon at the authors institution with at least 6 months of follow-up. These patients were compared with 30 patients who did not have a workers compensation claim. The workers compensation group had a Hip Outcome Score of 66.5±28.8 and the non-workers compensation group had a Hip Outcome Score of 89.4±12.0. This difference was statistically significant with Wilcoxon test (P=.003). The workers compensation group had an average modified Harris Hip Score of 72.5±20.7 (mean±SD), and the non-workers compensation group had a modified Harris Hip Score of 75.6±15.3. This difference was not significantly significant with Wilcoxon test (P=.9). At latest follow-up, 15 patients in the workers compensation group (58%) were working. Patients returned to work an average of 6.8 months after surgery. The current study showed that postoperative functional outcomes in the workers compensation group, as measured by Hip Outcome Score, were significantly inferior to those in the non-workers compensation group. No statistical difference in postoperative modified Harris Hip Score was seen.

Intraoperative Radiation Exposure During Hip Arthroscopy

Background: The frequency of hip arthroscopy for the treatment of acute and chronic chondrolabral pathology and femoroacetabular impingement (FAI) has increased exponentially over the past decade. While surgeon and patient radiation exposure has been well documented in other areas of the orthopaedic literature, little is known about the procedure-specific and cumulative doses affecting the hip arthroscopist. Purpose: To determine the mean annual radiation exposure to the hip arthroscopist and the mean surgeon exposure per case. Study Design: Case series; Level of evidence, 4. Methods: A total of 210 consecutive hip arthroscopies performed in 209 patients by a single surgeon at a single ambulatory surgical center in a cohort consisting of approximately 50% bony (cam and pincer) pathology were prospectively reviewed, documenting the specific procedures performed in each case and the readings from a radiation dosimeter worn by the surgeon during positioning and while performing the procedures. Radiation readings for deep dose–equivalent (DDE), lens dose–equivalent (LDE), and shallow dose–equivalent (SDE) were measured. These readings were compared with the annual radiation dose limit recommendations established by the International Commission on Radiological Protection (ICRP). Results: The total radiation doses for the operative surgeon during all 210 cases were 183 mrem (1.83 mSv) DDE, 183 mrem (1.83 mSv) LDE, and 176 mrem (1.76 mSv) SDE. The mean exposure per case was 0.871 mrem (0.00871 mSv) DDE, 0.871 mrem (0.00871 mSv) LDE, and 0.838 mrem (0.00838 mSv) SDE. The operative surgeon’s mean annual exposure, performing 70 hip arthroscopies per year with 55% involving bony work, was 61.0 mrem (0.610 mSv) DDE, 61.0 mrem (0.610 mSv) LDE, and 58.7 mrem (0.587 mSv) SDE. These results are well below the ICRP annual limits of 50,000 mrem (500 mSv) DDE, 2000 mrem (20 mSv) LDE, and 50,000 mrem (500 mSv) SDE. Conclusion: For an experienced hip arthroscopist utilizing fluoroscopy during setup and bony resection, the annual and per-patient exposure to radiation remains well below the recommended ICRP limits. Clinical Relevance: Considering the increasing annual frequency of hip arthroscopies being performed, information regarding procedure-specific and cumulative doses of radiation exposure affecting the hip arthroscopist may provide valuable safety information for the orthopaedic community.

Hip Dysplasia: Prevalence, Associated Findings, and Procedures From Large Multicenter Arthroscopy Study Group

PURPOSEnTo report observational findings of patients with acetabular dysplasia undergoing hip arthroscopy.nnnMETHODSnWe performed a comparative case series of multicenter registry patients from January 2014 to April 2016 meeting the inclusion criteria of isolated hip arthroscopy, a documented lateral center-edge angle (LCEA), and completion of preoperative patient-reported outcome measures. A retrospective analysis compared range of motion, intra-articular pathology, and procedures of patients with dysplasia (LCEA ≤25°) and patients without dysplasia (LCEA >25°).nnnRESULTSnOf 1,053 patients meeting the inclusion criteria, 133 (13%) had dysplasia with a mean LCEA of 22.8° (standard deviation, 2.4°) versus 34.6° (standard deviation, 6.3°) for non-dysplasia patients. There were no statistically significant differences in preoperative modified Harris Hip Score, International Hip Outcome Tool-12 score, or visual analog scale score (pain). Cam deformity occurred in 80% of dysplasia patients. There was a significant difference in internal rotation between the dysplasia (21°) and non-dysplasia groups (16°, P < .001). Mean internal rotation (33.5°; standard deviation, 15.6°) of the dysplastic subjects without cam morphology was greater than that of the dysplastic patients with cam morphology (18.5°; standard deviation, 11.6°; P < .001). Hypertrophic labra were found more commonly in dysplastic (33%) than non-dysplastic hips (11%, P < .001). Labral tears in patients with dysplasia were treated by repair (76%), reconstruction (13%), and selective debridement (11%); labral treatments were not significantly different between cohorts. The most common nonlabral procedures included femoroplasty (76%) and synovectomy (73%). There was no significant difference between the dysplasia and non-dysplasia groups regarding capsulotomy types and capsular closure rates (96% and 92%, respectively).nnnCONCLUSIONSnDysplasia, typically of borderline to mild severity, comprises a significant incidence of surgical cases (13%) by surgeons performing high-volume hip arthroscopy. Despite having similar preoperative pain and functional profiles to patients without dysplasia, dysplasia patients may have increased flexed-hip internal rotation. Commonly associated cam morphology significantly decreases internal rotation. Arthroscopic labral repair, femoroplasty, and closure of interportal capsulotomy are the most commonly performed procedures.nnnLEVEL OF EVIDENCEnLevel III, therapeutic comparative case series.

Sex-Dependent Differences in Preoperative, Radiographic, and Intraoperative Characteristics of Patients Undergoing Hip Arthroscopy: Results From the Multicenter Arthroscopic Study of the Hip Group

PURPOSEnTo compare preoperative, radiographic, and intraoperative findings between male and female patients undergoing hip arthroscopy.nnnMETHODSnWe performed a retrospective review of a multicenter registry of patients undergoing hip arthroscopy between January 2014 and January 2017. Perioperative data from patients who consented to undergo surgery and completed preoperative patient-reported outcome questionnaires were analyzed to determine the effect of sex on preoperative symptoms, patient-reported outcomes, radiographic measures, and surgical procedures.nnnRESULTSnA total of 1,437 patients (902 female and 535 male patients) with a mean age of 34xa0years were enrolled in the study. Female patients reported greater pain preoperatively on a visual analog scale (55.42 vs 50.40, Pxa0= .001) and deficits in functional abilities as per the modified Harris Hip Score (53.40 vs 57.83, P < .001) and International Hip Outcome Tool 12 (31.21 vs 38.51, Pxa0= .001) than male patients. There was a significant difference in the alpha angle (67.6° in male patients vs 59.5° in female patients, P < .001) corresponding with a higher prevalence of cam deformity in male patients (94.6% vs 84.5%, P < .001). Male patients had less range of motion in flexion (-5.67°, P < .001), internal rotation (-8.23°, P < .001), and external rotation (-4.52°, P < .001) than female patients. Acetabular chondroplasty was performed in 58% of male patients versus 40.2% of female patients (P < .001). Acetabuloplasty was performed in 59.1% of male patients versus 43.9% of female patients (P < .001).nnnCONCLUSIONSnMale and female patients undergoing hip arthroscopy differ statistically in terms of preoperative hip function, hip morphology, and self-reported functional deficits, as well as the prevalence of surgical procedures. However, they do not differ significantly in terms of symptom localization, duration, or onset. The observed differences in preoperative functional scores between sexes, although statistically significant, may not represent clinically meaningful differences.nnnLEVEL OF EVIDENCEnLevel III, retrospective cross-sectional study.

Surgeon Radiation Exposure in Hip Arthroscopy A Prospective Analysis

Objectives: Hip arthroscopy is an established field within orthopaedic surgery. The majority of the procedures involve repairs of the acetabular labrum and arthroscopic treatment of femoroacetabular impingement (FAI). The procedures are being performed with increasing frequency annually. Fluoroscopic guidance is recommended during these procedures, and radiation exposure to the surgeon, staff, and patient remains a valid concern. The purpose of this study is to measure radiation exposure to the surgeon during hip arthroscopy and determine if this exposure remains below recommended annual occupational radiation exposure thresholds recommended by the International Committee on Radiological Protection (IRCP). Methods: Prospectively, radiation exposure was measured for a single surgeon at a single outpatient facility for all hip arthroscopic procedures over a three-year period. A radiation dosimeter was worn outside of the surgeons chest on the lead apron. Standard pre-operative and intra-operative imaging was used for all patients. Radiation readings were prospectively measured for deep dose equivalent (DDE), lens dose equivalent (LDE), and shallow dose equivalent (SDE). The cumulative radiation exposure was tabulated in millirem (mrem), converted to milli-Sieverts (mSv) (standard measurement used by the IRCP) and then the per-patient exposure calculated as well as annual exposure for 100 hip arthroscopies per year. Results: Between July 2011 and July 2014, 209 patients underwent a total of 280 hip arthroscopy procedures at a single facility by a single surgeon. There were 90 labral repairs, 83 femoroplasties, 26 acetabuloplasties, 66 labral debridements, 8 trochanteric bursectomies, and 7 iliopsoas releases. The cumulative DDE was 183 mrem (1.83 mSv), LDE 183 mrem (1.83 mSv), and SDE 176 mrem (1.76 mSv). The calculated per patient exposure for the surgeon was DDE 0.875 mrem (0.00875 mSv), LDE 0.875 mrem (0.00875 mSv), and SDE 0.842 mrem (0.00843 mSv). Calculated annual exposure for a surgeon performing 100 hip arthroscopies per year are DDE 8.75 mrem (0.0875 mSv), LDE 8.75 mrem (0.0875 mSv), and SDE 8.43 mrem (0.0842 mSv). Conclusion: Hip arthroscopy & hip preservation procedures are being performed with increasing frequency annually. Fluoroscopic guidance is recommended for safe entrance into the central compartment and during various parts of the procedures. Radiation exposure to the surgeon, staff, and patient is a valid concern. The IRCP sets recommended annual safety thresholds for occupational radiation exposure. Current annual safety thresholds are 50,000 mrem (500 mSv) to the hands, 50,000 mrem (500 mSv) to the skin, hands & feet, 15,000 mrem (150 mSv) to the eye, and 30,000 mrem (300 mSv) to the thyroid of healthcare workers. Our study shows surgeon radiation exposure below the annual safety thresholds recommended by the IRCP for 100 cases per year. For surgeons performing more than 100 hip arthroscopic procedures annually, the exposure will be higher. Appropriate safety equipment such as lead aprons, thyroid shields, and leaded glasses are still recommended, especially for high volume hip arthroscopists.

Incidence and Characterization of Injury to the Infrapatellar Branch of the Saphenous Nerve after ACL Reconstruction: A Prospective Study

Objectives: The infrapatellar branch of the saphenous nerve is commonly injured in anterior cruciate ligament reconstruction (ACLR) causing sensory deficits around the knee. The primary purpose of this prospective study was to determine the incidence of patient reported sensory deficits around the knee following ACLR. The secondary purpose was to determine if sensory deficits caused by intraoperative injury present at 6 weeks changed in severity and total area after 6 months and 1 year postoperatively. Methods: Two-hundred and fifty patients that underwent ACLR with or without meniscal repair were prospectively enrolled. Variables for each patient included: type of graft, direction of tibial incision, number of portals, and length of surgical incision. The grafts used were categorized into three types: Allograft (allo), hamstring autograft (HS), or patella tendon autograft (BTB). At 6 weeks, patients completed a questionnaire to ascertain any sensory deficits over their knee. Patients rated their sensory deficit on a scale from 0-10 (“0” = (no deficit) to “10” (complete lack of sensation) and shaded areas on a picture of a knee split into nine rectangular segments (3 by 3 grid) to determine the location of any numbness. Patients completed the same questionnaire at 6 months and 1 year. Any patient that was noted to have no stated numbness at 6 weeks or 6 months was noted to have completed the study. A mixed effects linear regression model was used to identify variables which were predictors for the patient-reported severity of numbness. Results: Overall, 67/221 (30.3%) patients who underwent ACLR stated that they had no numbness at 6 weeks. Of those patients who reported numbness at 6 weeks, 16.6% (25/151) considered their numbness completely resolved by six months. At 1 year, 73.2% (90/123) reported their numbness had gotten better and 14.2% (18/123) considered their numbness resolved. The most common location of numbness was along the inferolateral aspect of the knee. The mean numbness rating for allografts was 2.73 +/- 0.32 (mean +/- standard error) at 6 weeks, decreasing to 1.04 +/- 0.26 at 6 months and 0.64 +/- 0.26 at 1 year for oblique and vertical incisions combined. A statistical model, controlling for time and incision direction, indicated that HS patients were 1.94 +/- 0.52 points higher than allograft patients across all time points, and BTB patients were 1.57 +/- 0.51 points higher than allo. However, there were no significant difference in mean numbness score between BTB and HS patients (p=0.521). Time had a negative impact on the patient reported severity of numbness score for all graft types. At 6 months this effect was -0.95 +/- 0.17 and at 1 year, -1.21 +/- 0.18. The use of BTB increased the mean numbness of affected segments by 0.67 +/- 0.23, while the use of a HS increased the mean numbness of segments by 0.39 +/- 0.21. The mean number of segments decreased slightly with time, down by 0.20 +/- 0.08 at 6 months (p=0.008) and 0.28+- 0.08 at 1 year (p=<0.001). Conclusion: Sensory deficits after ACLR follow the direction of the infrapatellar branch of the saphenous nerve. Patients who underwent ACLR with allo were less likely to develop sensory deficits compared to BTB or HS. Sensory deficits in allo patients were on average, less severe. Surprisingly, there was no significant difference in numbness between HS and BTB grafts. Surgeons should counsel their patients that sensory deficits are common postoperatively after ACLR, but that this sensory disturbance is likely to dissipate with time.