Biomechanical Analysis of Ideal Knee Flexion Angle for ACL Graft Tensioning Utilizing Multiple Femoral and Tibial Tunnel Locations.

Anterior cruciate ligament (ACL) graft failure rate has been reported to be greater than 5% at 5 years. Our study evaluated ACL excursion with anatomic and nonanatomic femoral and tibial tunnels to determine optimal flexion angle to tension the ACL to minimize excursion. Ten cadaveric knee specimens were used. The ACL was sectioned and the femoral and tibial attachments were marked. A 1/16-inch drill created a tunnel in the center of the ACL footprint on the tibia and femur and additional tunnels were made 5 mm from this. A suture was passed through each tunnel combination and attached to a string potentiometer. The knee was ranged from full extension to 120 degrees of flexion for 10 cycles while mounted in a custom fixture. The change in length (excursion) of the suture during movement was recorded for each combination of femoral and tibial tunnels. Anatomic reconstruction of the ACL with tunnel placement in the center of the femoral and tibial footprint did not result in an isometric graft, with excursion of the ACL during knee motion of 7.46 mm (standard deviation [SD]: 2.7mm), greatest at 2.84 degrees of flexion (SD: 4.22). The tunnel combination that resulted in the least excursion was a femoral footprint 5 mm anterior to the femoral and 5 mm posterior to the tibial footprint (4. 2mm, SD: 1.37 mm). The tunnel combination that resulted in the most excursion utilized femoral footprint 5 mm proximal to the femoral and 5 mm posterior to the tibial footprint (9.81 mm, SD: 2.68 mm). Anatomic ACL reconstruction results in significant excursion of the ACL throughout motion. If not tensioned properly, the ACL can stretch during range of motion, potentially leading to rerupture. To prevent stretching of the graft, the current biomechanical study recommends tensioning an anatomic ACL reconstruction at its point of maximal excursion, or between 0 and 5 degrees of flexion. The level of evidence is IV.

Bone Marrow Edema, Clinical Significance, and Treatment Options: A Review.

Bone marrow edema (BME) is a descriptive term used to describe high-signal intensity changes detected on magnetic resonance fluid-sensitive sequences that could be attributed to a number of underlying pathologies. Regardless of the cause, physiologic remodeling of the subchondral bone can be limited because of ongoing joint forces, increased focalization of stress, and reduced healing capacity of the subchondral bone. BME is a known prognostic factor associated with pain, dysfunction, and progressive cartilage damage. This review summarizes the current known causes of BMEs, theories related to histopathological changes, and current treatment options including novel biologic surgical options.

Investigating the Bias in Orthopaedic Patient-reported Outcome Measures by Mode of Administration: A Meta-analysis.

BACKGROUND: Patient-reported outcome measures (PROMs) are critical and frequently used to assess clinical outcomes to support medical decision-making. QUESTIONS/PURPOSE: The purpose of this meta-analysis was to compare differences in the modes of administration of PROMs within the field of orthopaedics to determine their impact on clinical outcome assessment. PATIENTS AND METHODS: The PubMed database was used to conduct a review of literature from 1990 to 2018 with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. All articles comparing PROMs for orthopaedic procedures were included and classified by the mode of administration. Each specific survey was standardized to a scale of 0 to 100, and a repeated random effectsmodel meta-analysis was conducted to determine the mean effect of each mode of survey. RESULTS: Eighteen studies were initially included in the study, with 10 ultimately used in the meta-analysis that encompassed 2384 separate patient survey encounters. Six of these studies demonstrated a statistically notable difference in PROM scores by mode of administration. The meta-analysis found that the standardized mean effect size for telephone-based surveys on a 100-point scale was 71.7 (SE 5.0) that was significantly higher (P , 0.0001) than survey scores obtained via online/tech based (65.3 [SE 0.70]) or self-administered/paper surveys (61.2 [SE 0.70]). CONCLUSIONS: Overall, this study demonstrated that a documented difference exists in PROM quality depending on the mode of administration. PROM scores obtained via telephone (71.7) are 8.9% higher than scores obtained online (65.3, P , 0.0001), and 13.8% higher than scores obtained via self-administered on paper (61.8, P , 0.0001). Few studies have quantified statistically notable differences between PROM scores based solely on the mode of acquisition in orthopaedic.

Can We Accurately Predict the Quadruple Hamstring Graft Diameter From Preoperative Magnetic Resonance Imaging?

BACKGROUND: Anterior cruciate ligament (ACL) reconstruction with a quadruple hamstring (QH) autograft is a widely utilized procedure with good outcomes. A graft diameter less than 8 mm, however, has been associated with higher revision rates. Accurately determining the diameter of the hamstring tendon preoperatively can help surgeons plan accordingly. PURPOSE/HYPOTHESIS: The purpose of our study was to determine whether QH graft size can be reliably predicted from preoperative magnetic resonance imaging (MRI) measurements. We hypothesized that we can achieve a high predicted QH graft size correlation with regard to preoperative and intraoperative measurements. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: We evaluated patients undergoing ACL reconstruction using QH autografts. At the time of surgery, the semitendinosus tendon (ST) and gracilis tendon (GT) were harvested and sized and then sized as a QH graft. Preoperative individual ST and GT sizes were determined from T2-weighted fat-saturated MRI at 3 cm above the joint line using correlating axial and coronal images. We then used a predictive chart to predict what the size of the QH graft would be and compared this with the actual measurements. Pearson correlation coefficients between predicted and actual graft sizes were calculated. RESULTS: The predicted GT graft size was within 0.5 mm of the actual size in 45 of 60 (75%) patients and within 1 mm of the actual graft size in 59 of 60 (98%) patients. The predicted GT graft size from MRI measurements correlated with the actual GT graft size (r = 0.62, P < .00001). The predicted ST graft size was within 0.5 mm of the actual size in 45 of 60 (75%) patients and within 1 mm of the actual graft size in 56 of 60 (93%) patients. The predicted ST graft size from MRI measurements correlated with the actual ST graft size (r = 0.71, P < .00001). The predicted QH graft size was within 0.5 mm of the actual size in 52 of 60 (87%) patients and within 1 mm of the actual graft size in 60 of 60 (100%) patients. The predicted QH graft size from MRI measurements correlated with the actual QH graft size (r = 0.81, P < .00001). CONCLUSION: The current technique can reliably predict the size of a QH graft within 1 mm of the final graft size.

Clinical Evaluation of an Arthroscopic Knotless Suprapectoral Biceps Tenodesis Technique: Loop 'n' Tack Tenodesis.

BACKGROUND: Pathology of the long head of the biceps tendon is a well-known cause of shoulder pain that is commonly managed with arthroscopic suprapectoral biceps tenodesis when conservative treatment fails. PURPOSE: To present an arthroscopic knotless suprapectoral biceps tenodesis technique known as "Loop 'n' Tack" tenodesis and to report the clinical outcomes of patients with a minimum 2 years of follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A retrospective review of all patients who had undergone Loop 'n' Tack tenodesis between January 2009 and May 2014 was completed. Charts were reviewed, and patients were contacted for demographic data, time from surgery, concomitant procedures, and workers' compensation status, as well as visual analog scale for pain, American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation, and University of California, Los Angeles (UCLA) scores. RESULTS: Complete follow-up evaluations were performed for 59 of 68 patients (87%). Mean follow-up was 43 months. A majority (88%) of patients had at least 1 additional procedure performed at the time of biceps tenodesis. The mean ASES shoulder score improved from 42.6 preoperatively to 91.0 postoperatively (P < .001), and 54 of 59 patients (91.5%) had a good/excellent outcome, with a UCLA shoulder score >27 and ASES shoulder score >70. Three patients (5%) reported biceps cramping pain with overuse, and 2 (3.3%) reported intermittent anterior shoulder pain. No patients had developed a "Popeye" deformity at final clinical examination, and 97% reported that they were overall satisfied with the procedure. CONCLUSION: The Loop 'n' Tack tenodesis technique results in a high rate of patient satisfaction, significant improvement in shoulder outcome scores, and a low incidence of postoperative pain, with no reoperations for biceps-related pathology.

An Algorithm for Diagnosing and Treating Primary and Recurrent Patellar Instability.

Major anatomic risk factors for recurrent patellar instability include trochlear dysplasia, patella alta, a lateralized tibial tuberosity, and medial patellofemoral ligament insufficiency. Acute first-time patellar dislocation may be treated nonoperatively in the absence of osteochondral injury. Recurrent patellar instability often requires medial patellofemoral ligament reconstruction, with osseous procedures reserved for patients with substantial underlying anatomic abnormalities. Surgical treatment of patellar instability is complex and should be individualized to address the needs of each patient.

Quadrupled Hamstring Graft Strength as a Function of Clinical Sizing.

PURPOSE: This study sought to compare the strength of quadrupled hamstring tendon (QHT) grafts of 6 to 9.5 mm in clinical diameter with that of 10-mm bone-patellar tendon-bone (BPTB) grafts. METHODS: Twenty cadaveric semitendinosus and gracilis tendons were combined into QHT grafts. These were sized using a standard graft-sizing device and an area micrometer, yielding grafts ranging from 6 to 9.5 mm in diameter. The grafts were tested to failure. Five 10-mm BPTB grafts were also sized and tested. RESULTS: Clinical sizing did predict the strength of the graft but not profoundly. As a material alone, without consideration of fixation in bone tunnels, QHT grafts were stronger than BPTB grafts. Graft strength decreased with size, but a linear relation between strength and diameter (r(2) = 0.715, P < .001) was found to be as good as the expected quadratic fit (r(2) = 0.709). Compared with BPTB grafts, even the smallest QHT grafts (diameter <6.5 mm) were still significantly stronger than 10-mm BPTB grafts (P = .004). The elastic moduli of the QHT and BPTB grafts were 761 ± 187 MPa and 615 ± 403 MPa, respectively; elongations at failure were 12.0% ± 2.0% and 7.5% ± 1.6%, respectively; and failure stresses were 105 ± 18 MPa and 50 ± 14 MPa, respectively. CONCLUSIONS: This work shows that a clinical size of QHT grafts of 6 mm in diameter is not a concern regarding the strength itself. For a possible lower-end prediction of acceptable size, assuming that a gracilis-semitendinosus graft would have only the stress of the weakest measured QHT graft of 88 MPa, a graft of 5.5 mm in diameter would suffice, having more strength in newtons than the average patellar tendon. CLINICAL RELEVANCE: Clinically sized QHT grafts have a higher failure strength than 10-mm patellar tendon grafts. Therefore the strength of the graft cannot account for the higher clinical failure rates of smaller hamstring grafts in active patients in clinical studies.

Technique for creating the anterior cruciate ligament femoral socket: optimizing femoral footprint anatomic restoration using outside-in drilling.

PURPOSE: The purpose of this study was to investigate and optimize anterior cruciate ligament (ACL) femoral outside-in drilling technique with a goal of anatomic restoration of the footprint morphologic length, width, area, and angular orientation. METHODS: Ex vivo, computer navigation was used to create virtual 3-dimensional maps of femoral bone tunnels for ACL drill guide pin insertion paths on small, medium, and large models of averaged femora considering various pin insertion angles to the femur. We then determined which pin insertion angle resulted in an ACL femoral footprint optimally matching normal human anatomic length, width, area, and angular orientation of the footprint long axis. RESULTS: During outside-in drilling of the ACL femoral socket, a guide pin entrance angle of 60° to a line perpendicular to the femoral anatomic axis, combined with a guide pin entrance angle of 20° to the transepicondylar axis, results in the closest approximation of the gold standard of normal anatomic morphology of the human knee ACL femoral footprint length, width, area, and angular orientation. CONCLUSIONS: During outside-in drilling of the ACL femoral socket, a guide pin entrance angle of 60° to a line perpendicular to the femoral anatomic axis, combined with a guide pin entrance angle of 20° to the transepicondylar axis, results in optimal reconstruction of the normal human anatomic ACL femoral footprint length, width, area, and angular orientation. CLINICAL RELEVANCE: We describe arthroscopic landmarks for anatomic ACL femoral socket creation that may be considered by practicing arthroscopic surgeons in the operating room, without open dissection or fluoroscopy and unaffected by type of drill guide or variations in the thickness of the femoral soft-tissue envelope.

Understanding bony safety zones in the posterior iliac crest: an anatomic study from the Hamann-Todd collection.

STUDY DESIGN: Morphometric analysis of the human ilia obtained from the Hamann-Todd Collection at Cleveland Museum of Natural History. OBJECTIVE: To identify whether gender and pelvis size affect the distances between anatomic landmarks of the posterior pelvis. SUMMARY OF BACKGROUND DATA: The iliac crest bone harvest is commonly performed in orthopedic, neurosurgic, and maxillofacial surgery. Morbidity from the bone graft harvest is well described (Arrington et al, Clin Orthop Relat Res 1996:300-9; Ebraheim et al, J Am Acad Orthop Surg 2001;9:210-8; Hu and Bohlman, Clin Orthop Relat Res 1994;208-13; Kahn, Clin Orthop Relat Res 1979;204-7; Kurz et al, Spine 1989;14:1324-31; Lim et al, Spine 1996;21:2376-8; Sasso et al, J Bone Joint Surg Am 1998;80:631-5; St. John et al, A J Orthop (Belle Mead NJ) 2003;32:18-23; Summers and Eisenstein, J Bone Joint Surg Br 1989;71:677-80). Several studies have advanced our understanding of the bony, vascular, and neurologic anatomy of the posterior iliac crest (Ebraheim et al, J Am Acad Orthop Surg 2001;9:210-8; Xu et al, Spine 1996;21:1017-20). There is no literature documenting the measurement of this region on a large, statistically significant scale. METHODS: An anatomic study was undertaken using the Hamann-Todd collection. The bilateral human ilia were examined from 50 men and 50 women between 18 and 80 years of age. Age, gender, and side were recorded. Four parameters were recorded: the shortest distance from the posterior superior iliac spine to the sciatic notch (PN), the shortest distance from posterior superior iliac spine to the sacroiliac joint (PS), the anterior-posterior length of the sciatic notch (P90), and the maximum length of the sacroiliac joint (SI). RESULTS: The right and left ilia were compared, and no significant difference was found. The mean for all 4 measurements was slightly larger in men and statistically significant (PN: men 43.7 +/- 4.6 mm vs. women 39.7 +/- 5.8 mm; PS: 21.5 +/- 7.8 mm vs. 16.9 +/- 5.3 mm; P90: 16.7 +/- 3.8 mm vs. 15.3 +/- 3.6 mm; SI: 60.0 +/- 5.9 mm vs. 55.2 +/- 5.8 mm). The ranges and distribution of data within the ranges were compared. Men had higher maximum limits although the lower limits were similar (PN: men 28.7-62.7 mm vs. women 28.0-51.0 mm; PS: 7.3-43.3 mm vs. 4.7-34.3 mm; P90: 9-25.3 mm vs. 7.7-22.7 mm; SI: 42.3-69 mm vs. 50.0-79.0 mm). CONCLUSION: This study defines distances in the posterior iliac crest beyond which the risk of injuring important structures is present (2.80 cm for 100% of the population or 3.00 cm for > or = 90%).

Complications of anterior cruciate ligament reconstruction.

Anterior cruciate ligament reconstruction has become one of the most common arthroscopic knee procedures, and it has excellent success rates. Intraoperative technical complications are uncommon but can be devastating to knee function. Each of the multiple steps in the reconstruction has associated complications.

Steroids and risk factors for airway compromise in multilevel cervical corpectomy patients: a prospective, randomized, double-blind study.

STUDY DESIGN: Prospective, randomized, double-blind study. OBJECTIVE: To evaluate intravenous corticosteroids in preventing delayed extubation after multilevel corpectomy and strut graft reconstructive procedures and to identify risk factors for delayed extubation in these patients. SUMMARY OF BACKGROUND DATA: We performed a prospective, randomized double-blind study in patients undergoing multilevel cervical corpectomy procedures. Our hypothesis was that high-dose perioperative steroids would decrease edema and thus decrease the incidence of delayed extubation. METHODS: We studied patients undergoing 2- or 3-level anterior cervical corpectomy procedures with anterior strut graft reconstruction. Sixty-six patients were randomized to receive 3 doses of either intravenous dexamethasone (n = 35) or saline (n = 31). The first dose was given before the incision, with subsequent doses given 8 and 16 hours later. Patients remained intubated until postoperative day 1, at which time a cuff leak test was performed by the anesthesiology attending. If a leak was present, the patient was extubated. If not, the test was repeated each postoperative day until a leak was present, indicating a patent airway. RESULTS: Five of 35 (14%) in the steroid group and 6 of 31 (19%) in the saline group required delayed extubation (P = 0.22). There were no statistical differences in preoperative parameters of age, gender, diagnosis, smoking history, BMI, number of operative levels, or preoperative American Society of Anesthesiologists rating between the 2 groups. Similarly there were no differences between the groups for duration of anesthesia, intraoperative colloids or crystalloids, intraoperative blood loss, or intraoperative urine output. The data for both groups were pooled to evaluate risk factors for delayed extubation. The only statistically significant risk factor for delayed extubation in this study was female gender (P = 0.0001). CONCLUSION: Based on our data, we cannot recommend intravenous dexamethasone for prevention of delayed extubation after multilevel anterior cervical corpectomy and strut grafting procedures.

Clinical outcome of a fibermetal taper stem: minimum 5-year followup.

Tapered femoral components were designed to provide a cementless alternative in patients with narrow femoral canals. Major concerns with this stem include perioperative fracture and thigh pain. To ascertain the frequency of these concerns, we retrospectively reviewed 100 consecutive hips in 97 patients who underwent total hip arthroplasty with a tapered fibermetal femoral component. Patients were evaluated postoperatively using Harris hip scores and sequential radiographs. The average age of the patients was 56.5 years (range, 33.7-73.5 years). Minimum followup was 5 years (average, 6.2 years; range, 5-9 years). One patient died at 1.3 years and was excluded from the study. Six patients had incomplete perioperative fractures of the calcar without extension below the lesser trochanter. All fractures were recognized perioperatively and fixed with cerclage wires without further problems. Four patients underwent revision surgery, two for recurrent dislocation secondary to malpositioning of the acetabular cup, one for a greater trochanteric fracture after a fall, and one for a fractured zirconium femoral head. At last followup, the mean Harris hip score was 98 (range, 86-100); two patients had mild anterior thigh pain. All femoral stems appeared to have bony integration radio-graphically. Tapered femoral stems provide a cementless alternative in patients with a narrow femoral canal without undue risk of perioperative fracture or thigh pain.

Clinical and histologic results related to a low-modulus composite total hip replacement stem.

BACKGROUND: Osteolysis secondary to stress shielding in patients with a total hip arthroplasty has been attributed to greater stiffness of the prosthetic femoral stem compared with the stiffness of the femur. This concern led to the development of a composite femoral stem implant with a structural stiffness similar to that of the native femur. The stem consists of a cobalt-chromium-alloy core surrounded by polyaryletherketone and titanium mesh for bone ingrowth. The purpose of this study was to determine the intermediate-term clinical, radiographic, and histologic results of the use of this stem. METHODS: Twenty-eight patients (nineteen men and nine women) with an average age of 51.3 years underwent primary total hip arthroplasty with the Epoch stem and were followed for an average of 6.2 years. Harris hip scores were determined and radiographic studies were performed preoperatively, postoperatively, and at two-year intervals thereafter. In addition, dual x-ray absorptiometry scans were made up to two years postoperatively to evaluate osseous resorption. Two femora obtained at autopsy thirteen and forty-eight months after surgery were analyzed for bone ingrowth and ongrowth. RESULTS: The Harris hip scores averaged 56 points preoperatively and improved to 97 points at the time of the last follow-up. Dual x-ray absorptiometry scans demonstrated the greatest decrease in mean bone density (27.5%) in Gruen zone 7 at two years. Radiographs demonstrated no instances of migration, and only one hip had osteolysis. All stems had stable osseous fixation. Histologic evaluation of the two femora that had been retrieved at autopsy at thirteen and forty-eight months showed the mean bone ingrowth (and standard deviation) along the entire length of the stem to be 49.62% +/- 13.04% and 73.57% +/- 8.48%, respectively, and the mean bone ongrowth to be 54.18% +/- 7.68% and 80.92% +/- 6.06%, respectively. CONCLUSIONS: Intermediate-term follow-up of hips treated with the Epoch stem indicated excellent clinical success, radiographic evidence of osseous integration, and histologic findings of osseous ingrowth and ongrowth. Although the implant has been associated with excellent results in both the short and the intermediate term, longer follow-up will be necessary to assess the long-term function of the implant.