Pain and functional outcomes of the sacroiliac joint after platelet-rich plasma injection: a descriptive review.

The purpose of this manuscript is to highlight and review the status of literature regarding efficacy of platelet-rich plasma (PRP) in the treatment of sacroiliac joint (SIJ) dysfunction. A review of the literature on PRP interventions on the SIJ or ligaments was performed. Seven studies had improvements in their respective primary end point and demonstrated a strong safety profile without any serious adverse events. Only five articles demonstrated clinical efficacy of >50% in their primary outcome measures. There appears to be inconsistent and insufficient evidence for a conclusive recommendation for or against SIJ PRP. There is a need for adequately powered well-designed, standardized, double-blinded randomized clinical trials to determine the effectiveness of PRP in SIJ-mediated pain.

Non-operative orthobiologic use for rotator cuff disorders and glenohumeral osteoarthritis: A systematic review.

BACKGROUND: Shoulder pain from rotator cuff pathology and glenohumeral osteoarthritis is a common entity encountered in musculoskeletal practices. Orthobiologic agents are being increasingly used as a treatment option and understanding their safety and efficacy is necessary. OBJECTIVE: To systematically evaluate the available evidence for orthobiologic use in rotator cuff and glenohumeral pathology. METHODS: A systematic review was undertaken following PRISMA guidelines. Randomized clinical trials (RCTs) and prospective cohort studies evaluating non-operative treatment with prolotherapy, platelet-rich plasma (PRP), or medicinal signaling cells (MSCs) for rotator cuff pathology and glenohumeral osteoarthritis were included. Bias risk assessments used were the Cochrane tool and Newcastle-Ottawa score. RESULTS: The search yielded 852 potential articles, of which 20 met the inclusion criteria with a breakdown of 5 prolotherapy, 13 PRP, and 2 MSC. Sixteen studies were RCTs and 4 were cohort studies. Six studies were deemed "low risk of bias or good quality". Efficacy results were mixed, and no serious adverse events were reported from orthobiologic treatment. CONCLUSIONS: Orthobiologics offer a relatively safe management option with inconclusive evidence for or against its use for rotator cuff pathology. No studies on glenohumeral osteoarthritis met the inclusion criteria. Adoption of standardized preparation reporting and consistent use of functional outcome measures is imperative for future studies to consider.

Evaluation of Endothelial and Vascular-Derived Progenitor Cell Populations in the Proximal and Distal UCL of the Elbow: A Comparative Study.

Background: Vascular-derived progenitor and endothelial cell populations (CD31, CD34, CD146) are capable of multipotent differentiation at the site of injured ligamentous tissue to aid in the intrinsic healing response. Proximal ulnar collateral ligament (UCL) tears have been reported to have better healing capability when compared with distal UCL tears. Purpose: To compare the vascular composition of the proximal and distal insertions of the anterior bundle of the UCL of the elbow via known markers of endothelial and vascular-derived progenitor cells (CD31, CD34, CD146). Study Design: Descriptive laboratory study. Methods: UCLs were harvested from 10 nonpaired fresh-frozen human cadaveric elbows and transected into proximal and distal portions. Endothelial and vascular-derived progenitor cell densities were assessed with 4 staining groups: CD31 (immunohistochemistry) and CD31/α-smooth muscle actin (α-SMA), CD34/α-SMA, and CD146/α-SMA (immunofluorescence). CD31 immunohistochemistry identified endothelial progenitor cells in the UCL. Later staining of the same slides with α-SMA demonstrated the relationship of progenitor cells to the surrounding vasculature. Fluorescent staining was quantified by calculating the proportion of positively stained nuclei versus the total number of nuclei in the proximal and distal UCL. Results: CD31+ cells were present in the proximal and distal sections of all 10 UCLs. Fluorescent staining revealed no significant differences in the ratio of CD31 to total nuclei between the distal (median, 36% [range, 23%-53%]) and proximal UCL (39% [22%-56%]) (P = .432, Wilcoxon signed-rank test). Similarly, no differences were seen between CD34 distal (39% [24%-64%]) and proximal regions (46% [28%-63%]) (P = .846, Wilcoxon signed-rank test) or CD146 distal (40% [12%-65%]) and proximal regions (40% [22%-51%]) (P ≥ .999, Wilcoxon signed-rank test). Conclusion: Analysis of UCL tissues demonstrated equal distributions of vascular endothelial and vascular-derived progenitor cell markers throughout the proximal and distal UCL. Unlike that of the medial collateral ligament of the knee, the microvascular composition of the proximal and distal UCL insertions was not different, suggesting a well-vascularized ligament throughout its course. Clinical Relevance: These findings investigate one of the possible contributors to UCL healing after injury, which may provide insight into operative and nonoperative management of UCL injuries in the future. This study also indicates that reasons other than differences in progenitor cell density alone may explain the clinical healing differences seen between proximal and distal UCL tears. A better understanding of the microvascular environment and associated blood supply is warranted to understand the healing capability of the UCL.

The forgotten joint: quantifying the anatomy of the proximal tibiofibular joint.

PURPOSE: Limited objective data exist detailing the quantitative anatomy of the individual bundles of the proximal tibiofibular joint and their relation to surgically pertinent osseous landmarks. The purpose of this study was to qualitatively and quantitatively describe the ligamentous anatomy of the proximal tibiofibular joint and its relation to relevant bony landmarks. METHODS: Ten non-paired, fresh-frozen cadaveric knee specimens were dissected to identify the proximal tibiofibular joint ligament bundles. Pertinent bony landmarks were identified and served as reference points for the tibial and fibular attachments for each bundle. Ligament bundle footprints, lengths and orientations were measured using a 3D coordinate measuring device. RESULTS: Up to four bundles were identified anteriorly and up to three bundles posteriorly. The inferior bundle was identified anteriorly and posteriorly in 60% and 20% of the cases, respectively. For the anterior complex, the centres of the tibial attachments were a mean distance of 12.5 mm (95% CI [10.7, 14.3]) and 25.3 mm (95% CI [21.6, 29.0]) from the tibial plateau for the superior and inferior bundles, respectively. The centres of the fibular attachments were 11.3 mm (95% CI [7.4, 15.1]) and 27.0 mm (95% CI [24.0, 30.0]) from the apex of the fibular styloid for the superior and inferior bundles, respectively. For the bundles of the posterior complex, the centres of the tibial attachments were 13.4 mm (95% CI [11.6, 15.2]) and 38.8 mm (95% CI [31.0, 46.6]) distal to the tibial plateau for the superior and inferior bundles, respectively, and the centres of the fibular attachments were 8.0 mm (95% CI [5.8, 10.1]) and 29.3 mm (95% CI [25.5, 33.1]) from the apex of the fibular styloid for the superior and inferior bundles, respectively. In the coronal plane, the mean 2D angle between the medial to lateral knee joint axis and the axis passing through the centre of the proximal tibiofibular joint and the centre of the tibial plateau was 16.9° (95% CI [12.8, 21.0]). CONCLUSION: The ligament bundles of the proximal tibiofibular joint were reproducibly identified between specimens in relation to surrounding bony landmarks. Up to four bundles were identified in the anterior ligament complex and up to three in the posterior complex. Variation in bundle orientation and footprint size was observed. Based on these findings, an anatomic reconstruction can be performed using surrounding reliable landmarks.

Qualitative and Quantitative Analyses of the Dynamic and Static Stabilizers of the Medial Elbow: An Anatomic Study.

BACKGROUND: The anterior bundle of the medial ulnar collateral ligament (UCL) and the forearm flexors provide primary static and dynamic stability to valgus stress of the elbow in overhead-throwing athletes. Quantitative anatomic relationships between the dynamic and static stabilizers have not been described. PURPOSE: To perform qualitative and quantitative anatomic evaluations of the medial elbow-UCL complex with specific attention to pertinent osseous and soft tissue landmarks. STUDY DESIGN: Descriptive laboratory study. METHODS: Ten nonpaired, fresh-frozen human cadaveric elbows (mean age, 54.1 years [range, 42-64 years]; all male) were utilized for this study. Quantitative analysis was performed with a 3-dimensional coordinate measuring device to quantify the location of pertinent bony landmarks and tendon and ligament footprints on the humerus, ulna, and radius. RESULTS: The anterior bundle of the UCL attached 8.5 mm (95% CI, 6.9-10.0) distal and 7.8 mm (95% CI, 6.6-9.1) lateral to the medial epicondyle, 1.5 mm (95% CI, 0.5-2.5) distal to the sublime tubercle, and 7.3 mm (95% CI, 6.1-8.5) distal to the joint line on the ulna along the ulnar ridge. The flexor digitorum superficialis (FDS) ulnar tendinous insertion was closely related and interposed within the anterior bundle of the UCL, overlapping with 45.6% (95% CI, 38.1-53.6) of the length of the anterior bundle of the UCL. The flexor carpi ulnaris (FCU) attached 1.9 mm (95% CI, 0.8-2.9) posterior and 1.3 mm (95% CI, 0.6-3.2) proximal to the sublime tubercle and overlapped with 20.9% (95% CI, 7.2-34.5) of the area of the distal footprint of the anterior bundle of the UCL. CONCLUSION: The anterior bundle of the UCL had consistent attachment points relative to the medial epicondyle and sublime tubercle. The ulnar limb of the FDS and FCU tendons demonstrated consistent insertions onto the ulnar attachment of the anterior bundle of the UCL. These anatomic relationships are important to consider when evaluating distal UCL tears both operatively and nonoperatively. Excessive stripping of the sublime tubercle should be avoided during UCL reconstruction to prevent violation of these tendinous attachments. CLINICAL RELEVANCE: The findings of this study enhance the understanding of valgus restraint in throwing athletes and provide insight into the difference in nonoperative outcomes between proximal and distal tears of the UCL.

Double-bundle posterior cruciate ligament reconstruction: a biomechanical analysis of simulated early motion and partial and full weightbearing on common reconstruction grafts.

PURPOSE: The purpose of this study was to determine the biomechanical effects of simulated immediate motion and weightbearing during rehabilitation on different double-bundle posterior cruciate ligament reconstruction (DB-PCLR) graft options. METHODS: Nine each of commercially prepared (allograft) Achilles tendon allografts, fresh-frozen (autograft) bone-patellar tendon-bone grafts, and fresh-frozen quadriceps tendon grafts were paired with commercially prepared anterior tibialis allografts, fresh-frozen semitendinosus grafts, and fresh-frozen semitendinosus grafts, respectively. Graft pairs were loaded to simulate early range of motion on a stationary bicycle, partial weightbearing (30 %), and full weightbearing. RESULTS: Acquired laxity (displacement, mm) between graft pairs was not significantly different during simulated early range of motion. However, during simulated partial weightbearing, the median acquired laxity of the patellar tendon/semitendinosus pair (1.06 mm) was significantly less than that of the quadriceps tendon/semitendinosus (1.50 mm, p = 0.01) and Achilles/anterior tibialis (1.44 mm, p = 0.003) graft pairs. During simulated full weightbearing, significantly less acquired laxity was observed for the patellar tendon/semitendinosus graft pair (2.38 mm) compared to the Achilles/anterior tibialis pair (4.85 mm, p = 0.04), but a significant difference was not observed compared to the QT/semitendinosus graft pair (3.91 mm, n.s.). There were no significant differences in the ultimate loads between any of the graft pairs. CONCLUSIONS: Simulated early range of motion and early partial weightbearing did not result in clinically significant acquired graft laxity in common graft options utilized for DB-PCLR. However, simulated full weightbearing did result in clinically significant acquired graft laxity, and therefore, early rehabilitation protocols should avoid implementing full weightbearing that could contribute to graft failure.

Medial Meniscus Radial Tear: A Transtibial 2-Tunnel Technique.

Complete radial tears of the medial meniscus significantly decrease the meniscal tissue's ability to dissipate tibiofemoral loads and have been described as functionally similar to a total meniscectomy, predisposing patients to early osteoarthritis. At present, no consensus exists regarding the optimal surgical treatment of a radial meniscal tear. Current repair techniques have led to a reportedly high rate of incomplete healing or healing of the meniscus in a nonanatomic, gapped position, which compromises its ability to withstand hoop stresses. Improvement regarding the ability to repair and heal medial meniscus radial tears has the potential to result in enhanced preservation of the articular cartilage in the medial compartment of the knee. This technical description details a method for repairing radial tears of the medial meniscus using a transtibial 2-tunnel technique.

Anatomic Double-Bundle Posterior Cruciate Ligament Reconstruction.

The posterior cruciate ligament (PCL) is known to be the main posterior stabilizer of the knee. Anatomic single-bundle PCL reconstruction, focusing on reconstruction of the larger anterolateral bundle, is the most commonly performed procedure. Because of the residual posterior and rotational tibial instability after the single-bundle procedure and the inability to restore the normal knee kinematics, an anatomic double-bundle PCL reconstruction has been proposed in an effort to re-create the native PCL footprint more closely and to restore normal knee kinematics. We detail our technique for an anatomic double-bundle PCL reconstruction using Achilles and anterior tibialis tendon allografts.

Two-Stage Revision Anterior Cruciate Ligament Reconstruction: Bone Grafting Technique Using an Allograft Bone Matrix.

Outcomes of primary anterior cruciate ligament (ACL) reconstruction have been reported to be far superior to those of revision reconstruction. However, as the incidence of ACL reconstruction is rapidly increasing, so is the number of failures. The subsequent need for revision ACL reconstruction is estimated to occur in up to 13,000 patients each year in the United States. Revision ACL reconstruction can be performed in one or two stages. A two-stage approach is recommended in cases of improper placement of the original tunnels or in cases of unacceptable tunnel enlargement. The aim of this study was to describe the technique for allograft ACL tunnel bone grafting in patients requiring a two-stage revision ACL reconstruction.

Surgical Techniques and Outcomes of Repairing Meniscal Radial Tears: A Systematic Review.

PURPOSE: To systematically review meniscal radial tear repair procedures and compare the techniques, outcomes, and complications. METHODS: Studies were identified through a systematic review of the literature using the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (1980-2014), Medline (1980-2014), and Embase. Inclusion criteria included a minimum follow-up of 24 months, English language, and publications from 1980 or later. Exclusion criteria were surgical techniques not reporting follow-up, biomechanical studies, cadaver/anatomic studies, and non-radial tear meniscal repair procedures. Meniscal radial repair, meniscal radial tear, meniscal radial tear repair, radial repair and radial tear were used as search terms. RESULTS: A total of 6 studies (55 patients) met the inclusion criteria. The mean duration of follow-up ranged from 24 to 71 months. Of the 6 studies, 5 reported radial tears to the lateral meniscus and 1 study reported cases of both medial and lateral meniscal radial tears. Two studies reported different inside-out repair techniques, 2 studies reported the use of an all-inside anchor-based repair system, 1 study reported an all-inside repair technique with absorbable sutures, and 1 study reported an inside-out repair with fibrin clots. Average postoperative Lysholm scores were reported in all 6 studies and ranged from 86.9 to 95.6. Average postoperative Tegner activity scores were reported in 4 studies and ranged from 1 to 6.7. The majority of studies concluded that their techniques produced satisfactory healing of the radial tear, without serious subsequent complications. CONCLUSIONS: Radial repair techniques differed among studies; however, postoperative subjective outcomes revealed patient improvement with repairing radial tears. With the increasing concern of long-term osteoarthritis after meniscectomy, meniscal preservation with repair of radial tears results in improved short-term clinical outcomes; however, long-term outcomes remain unknown. LEVEL OF EVIDENCE: Level IV, systematic review of level IV studies.

Qualitative and quantitative measurement of the anterior and posterior meniscal root attachments of the New Zealand white rabbit.

BACKGROUND: The purpose of this study was to quantify the meniscal root anatomy of the New Zealand white rabbit to better understand this animal model for future in vitro and in vivo joint degeneration studies. METHODS: Ten non-paired fresh frozen New Zealand white rabbit knee stifle joints were carefully disarticulated for this study. Measurements were made for all bony landmarks and ligamentous structure attachment sites on the tibial plateau. The following soft tissue structures were consistently identified in the rabbit stifle joint: the anterior root attachment of the lateral meniscus, the anterior root attachment of the medial meniscus, the anterior cruciate ligament, the posterior root attachment of the medial meniscus, the ligament of Wrisberg, the posterior cruciate ligament, and the posterior meniscotibial ligament. The following bony landmarks were consistently identified: the extensor digitorum longus groove, the medial tibial eminence, the center of the tibial tuberosity, and the lateral tibial eminence. RESULTS: The center of the anterior cruciate ligament and the medial tibial eminence apex were found to be 3.4 ± 0.3 mm (2.9-3.6) and 6.1 ± 0.6 mm (5.1-7.0) respectively from the center of the medical anterior root attachment. The center of the anterior cruciate ligament and the lateral tibial eminence apex were found to be 2.1 ± 0.5 mm (1.2-2.7) and 7.0 ± 0.6 mm (6.4-8.2) respectively from the center of the lateral anterior root attachment. The center of the posterior cruciate ligament and the medial tibial eminence apex were found to be 2.0 ± 0.7 mm (0.5-2.6) and 1.8 ± 0.4 mm (1.2-2.4) respectively from the center of the medial posterior root attachment. CONCLUSIONS: This study augments our understanding of the comparative anatomy of the rabbit stifle joint. This information will be useful for future biomechanical, surgical, and in vitro studies utilizing the rabbit stifle as a model for human knee joint degenerative diseases.

Influence of lateral meniscal posterior root avulsions and the meniscofemoral ligaments on tibiofemoral contact mechanics.

PURPOSE: The purpose of this study was to investigate the effect of lateral meniscal posterior root avulsions combined with intact meniscofemoral ligaments (MFLs), deficient MFLs, anterior cruciate ligament (ACL) tears and reconstructions, and root repairs using an established tibiofemoral contact mechanics testing protocol. METHODS: Ten fresh-frozen cadaveric knees were tested with six knee conditions (1: intact; 2: lateral meniscal posterior root avulsion; 3: root avulsion and deficient MFLs; 4: condition 3 with ACL tear; 5: condition 4 with ACL reconstruction; 6: ACL reconstruction with root repair) at five flexion angles (0°, 30°, 45°, 60°, and 90°), under a 1000-N axial load. Contact area and pressure were measured with Tekscan sensors. RESULTS: Compared to the intact state, condition 2 did not significantly change lateral compartment contact area or pressure. Changes in contact mechanics were greater at increased flexion angles; for condition 3 at 0° and 90°, contact area decreased 37 and 52 % [95 % CI (21-53) and (39-66), respectively] and mean contact pressure increased 55 and 87 % [95 % CI (33-76) and (59-114), respectively]. Root repair with ACL reconstruction was not significantly different from the intact state. CONCLUSIONS: The MFLs protect the lateral compartment from changes in contact mechanics in the setting of a lateral meniscal posterior root avulsion, whereas a combination of lateral meniscal root avulsion and deficient MFLs leads to significant changes. Concurrent ACL reconstruction and lateral meniscal root repair restore mean contact pressure and area to the intact state and are recommended in this combined injury to prevent or slow the development of lateral compartment arthritis.

A Novel Repair Method for Radial Tears of the Medial Meniscus: Biomechanical Comparison of Transtibial 2-Tunnel and Double Horizontal Mattress Suture Techniques Under Cyclic Loading.

BACKGROUND: Complete radial tears of the medial meniscus have been reported to be functionally similar to a total meniscectomy. At present, there is no consensus on an ideal technique for repair of radial midbody tears of the medial meniscus. Prior attempts at repair with double horizontal mattress suture techniques have led to a reportedly high rate of incomplete healing or healing in a nonanatomic (gapped) position, which compromises the ability of the meniscus to withstand hoop stresses. HYPOTHESIS: A newly proposed 2-tunnel radial meniscal repair method will result in decreased gapping and increased ultimate failure loads compared with the double horizontal mattress suture repair technique under cyclic loading. STUDY DESIGN: Controlled laboratory study. METHODS: Ten matched pairs of male human cadaveric knees (average age, 58.6 years; range, 48-66 years) were used. A complete radial medial meniscal tear was made at the junction of the posterior one-third and middle third of the meniscus. One knee underwent a horizontal mattress inside-out repair, while the contralateral knee underwent a radial meniscal repair entailing the same technique with a concurrent novel 2-tunnel repair. Specimens were potted and mounted on a universal testing machine. Each specimen was cyclically loaded 1000 times with loads between 5 and 20 N before experiencing a load to failure. Gap distances at the tear site and failure load were measured. RESULTS: The 2-tunnel repairs exhibited a significantly stronger ultimate failure load (median, 196 N; range, 163-212 N) than did the double horizontal mattress suture repairs (median, 106 N; range, 63-229 N) (P = .004). In addition, the 2-tunnel repairs demonstrated decreased gapping at all testing states (P < .05) with a final measured gapping of 1.7 mm and 4.1 mm after 1000 cycles for the 2-tunnel and double horizontal mattress suture repairs, respectively. CONCLUSION: The 2-tunnel repairs displayed significantly less gapping distance after cyclic loading and had significantly stronger ultimate failure loads compared with the double horizontal mattress suture repairs. CLINICAL RELEVANCE: Complete radial tears of the medial meniscus significantly decrease the ability of the meniscus to dissipate tibiofemoral loads, predisposing patients to early osteoarthritis. Improving the ability to repair medial meniscal radial tears in a way that withstands cyclic loads and heals in an anatomic position could significantly improve patient healing rates and result in improved preservation of the articular cartilage of the medial compartment of the knee. The 2-tunnel repair may be a more reliable and stronger repair option for midbody radial tears of the medial meniscus. Clinical studies are warranted to further evaluate these repairs.

A Biomechanical Comparison of an Open Repair and 3 Minimally Invasive Percutaneous Achilles Tendon Repair Techniques During a Simulated, Progressive Rehabilitation Protocol.

BACKGROUND: While the nonoperative management of Achilles tendon ruptures is a viable option, surgical repair is preferred in healthy and active populations. Recently, minimally invasive percutaneous repair methods with assistive devices have been developed. HYPOTHESIS/PURPOSE: The purpose of this study was to biomechanically analyze 3 commercially available, minimally invasive percutaneous techniques compared with an open Achilles repair during a simulated, progressive rehabilitation program. It was hypothesized that no significant biomechanical differences would exist between repair techniques. STUDY DESIGN: Controlled laboratory study. METHODS: A simulated, midsubstance Achilles rupture was created 6 cm proximal to the calcaneal insertion in 33 fresh-frozen cadaveric ankles. Specimens were then randomly allocated to 1 of 4 different Achilles repair techniques: (1) open repair, (2) the Achillon Achilles Tendon Suture System, (3) the PARS Achilles Jig System, or (4) an Achilles Midsubstance SpeedBridge Repair variation. Repairs were subjected to a cyclic loading protocol representative of progressive postoperative rehabilitation: 250 cycles at 1 Hz for each loading range: 20-100 N, 20-200 N, 20-300 N, and 20-400 N. RESULTS: The open repair technique demonstrated significantly less elongation (5.2 ± 1.1 mm) when compared with all minimally invasive percutaneous repair methods after 250 cycles (P < .05). No significant differences were observed after 250 cycles between the Achillon, PARS, or SpeedBridge repairs, with mean displacements of 9.9 ± 2.2 mm, 12.2 ± 4.4 mm, and 10.0 ± 3.9 mm, respectively. When examined over smaller cyclic intervals, the majority of elongation, regardless of repair, occurred within the first 10 cycles. Within the first 10 cycles, open repairs achieved 71.2% of the total elongation observed after 250 cycles. Corresponding values for the Achillon, PARS, and SpeedBridge repairs were 81.8%, 77.9%, and 69.0%, respectively. No significant differences were observed in the total number of cycles to failure between minimally invasive percutaneous repairs and open repairs. Minor differences in the mechanism of failure were noted; however, the majority of all repairs failed at the suture-tendon interface. CONCLUSION: Minimally invasive percutaneous repair techniques demonstrated a susceptibility to significant early repair elongation when compared with open repairs. However, the ultimate strengths of repairs (cycles to failure) were comparable across all techniques. CLINICAL RELEVANCE: The reduced early elongation of open repairs suggests that patients treated with this technique may be able to progress through an earlier and/or more aggressive postoperative rehabilitation protocol with a lower risk of early irrevocable repair elongation or gapping about the repair site. However, in cases where cosmesis or wound-healing complications are of significant concern, minimally invasive percutaneous techniques provide a biomechanically reasonable alternative based on their repair strengths (cycles to failure). These repairs may need to be protected longer postoperatively to allow for biological healing and avoid early repair elongation and potential gapping between the healing tendon ends.

Emerging Updates on the Posterior Cruciate Ligament: A Review of the Current Literature.

The posterior cruciate ligament (PCL) is recognized as an essential stabilizer of the knee. However, the complexity of the ligament has generated controversy about its definitive role and the recommended treatment after injury. A proper understanding of the functional role of the PCL is necessary to minimize residual instability, osteoarthritic progression, and failure of additional concomitant ligament graft reconstructions or meniscal repairs after treatment. Recent anatomic and biomechanical studies have elucidated the surgically relevant quantitative anatomy and confirmed the codominant role of the anterolateral and posteromedial bundles of the PCL. Although nonoperative treatment has historically been the initial treatment of choice for isolated PCL injury, possibly biased by the historically poorer objective outcomes postoperatively compared with anterior cruciate ligament reconstructions, surgical intervention has been increasingly used for isolated and combined PCL injuries. Recent studies have more clearly elucidated the biomechanical and clinical effects after PCL tears and resultant treatments. This article presents a thorough review of updates on the clinically relevant anatomy, epidemiology, biomechanical function, diagnosis, and current treatments for the PCL, with an emphasis on the emerging clinical and biomechanical evidence regarding each of the treatment choices for PCL reconstruction surgery. It is recommended that future outcomes studies use PCL stress radiographs to determine objective outcomes and that evidence level 1 and 2 studies be performed to assess outcomes between transtibial and tibial inlay reconstructions and also between single- and double-bundle PCL reconstructions.

A mandated change in goalie pad width has no effect on ice hockey goaltender hip kinematics.

OBJECTIVE: To determine hip kinematics and ground impact forces of the butterfly movement in ice hockey goaltenders for the pre-2005/06 season pads (30.5 cm) versus the current regulation width pads (27.9 cm). DESIGN: Prospective laboratory controlled study. SETTING: Research Institute BioMotion Laboratory. PARTICIPANTS: Ten male ice hockey goaltenders at the Midget AA level or higher. ASSESSMENT OF RISK FACTORS: The participants performed butterfly motions wearing 3 different types of leg pads in a randomized order: own 27.9 cm, standard 27.9 cm, and standard 30.5 cm. In addition, this study investigated hip kinematics and ground impact forces in the pre-2005/06 season pads versus the current regulation width pads. MAIN OUTCOME MEASURES: Kinematics and kinetics were calculated using motion analysis software. RESULTS: The knee ground reaction force upon landing was 1.45 ± 0.43 times the body weight. Hip internal rotation was reduced when goaltenders wore their own, previously "broken-in," set of pads as compared with the set of standard, new 27.9-cm pads (17.5 ± 4.8 vs 20.1 ± 4.8 degrees, respectively; P = 0.032). The recent mandated change in goalie pad from 30.5- to 27.9-cm width had no significant effect on hip kinematics. However, previously worn versus new pads did have an effect on hip kinematics. CONCLUSIONS: The butterfly movement placed ice hockey goaltenders' hips at their passive limits of hip internal rotation and involved knee forces 1.45 times the body weight. The recent mandated change in goalie pad from 30.5- to 27.9-cm width had no significant effect on hip kinematics. However, previously worn versus new pads did have an effect on hip kinematics.

Qualitative and quantitative anatomic analysis of the posterior root attachments of the medial and lateral menisci.

BACKGROUND: The clinical importance of the meniscal posterior root attachments has been recently reported by both biomechanical and clinical studies. Although several studies have been performed to evaluate surgical techniques, there have been few studies on the quantitative arthroscopically pertinent anatomy of the posterior meniscal root attachments. HYPOTHESIS: The posterior root attachments of the medial and lateral menisci are consistent among specimens, and repeatable quantitative measurements using arthroscopically pertinent landmarks are achievable. STUDY DESIGN: Descriptive laboratory study. METHODS: Twelve nonpaired, fresh-frozen cadaveric knees were used. The positions of the posterior root attachments of the medial and lateral menisci were identified, and 3-dimensional measurements to arthroscopically pertinent landmarks were performed using a coordinate measuring system. RESULTS: The direct distance (±standard error of the mean) between the medial tibial eminence apex and the medial meniscus posterior root attachment center was 11.5 (±0.9) mm. When split into directional components along the knee's main axes, the medial meniscus posterior root attachment center was 9.6 (±0.8) mm posterior and 0.7 (±0.4) mm lateral along the bony surface from the medial tibial eminence apex. It was located 3.5 (±0.4) mm lateral from the medial articular cartilage inflection point and directly 8.2 (±0.7) mm from the nearest tibial attachment margin of the posterior cruciate ligament. The direct distance between the lateral tibial eminence apex and the lateral meniscus posterior root attachment center was 5.3 (±0.3) mm. When it was split into directional components using the knee's main axes, the lateral meniscus posterior root attachment center was 4.2 (±0.4) mm medial and 1.5 (±0.7) mm posterior from the lateral tibial eminence apex. The lateral meniscus posterior root attachment center was located 4.3 (±0.5) mm medial from the nearest articular cartilage margin and directly 12.7 (±1.1) mm from the nearest margin of the tibial attachment of the posterior cruciate ligament. CONCLUSION: This quantitative study reproducibly identified the posterior root attachment centers of the medial and lateral menisci in relation to arthroscopically pertinent landmarks and guidelines. CLINICAL RELEVANCE: These data can be directly applied to assist in anatomic meniscal root repairs.