Ryan Krupp

Arthroscopic suture bridge transosseus equivalent fixation of rotator cuff tendon preserves intratendinous blood flow at the time of initial fixation

BACKGROUND Current etiologic theories concerning healing rates in rotator cuff repair have focused on the blood supply in the tendinous portion of the cuff. We currently have little information regarding the effect of our repair techniques on this critical variable. We hypothesize that intratendinous blood flow is changed during transosseus equivalent tendon fixation. METHODS Eighteen consecutive patients with rotator cuff tears amenable to double row fixation were included in the study. Each patient underwent a standard arthroscopic transosseous equivalent double row fixation procedure using the Arthrex SutureBridge technique (Arthrex, Naples, FL, USA). After tying down of the medial row, a first set of recordings was taken using a custom laser doppler flowmetry probe (Perimed, Inc., Ohio, USA). A second recording was made following securing of the lateral PushLock anchors. The data were compared to determine the overall effect on blood flow associated with this technique. RESULTS Summated averages for the 2 groups show a significant (44.67%) decline in the blood flow present after the second row of implants are placed (P < .01). Individual calculations for regions of the cuff tear indicate significant differences in anterior third (P = .01), middle third (P < .01), and posterior third (P = .02) of the tear after transosseous equivalent fixation. CONCLUSION Completion of the construct with lateral anchors in the transosseous equivalent technique results in reduced but preserved blood flow in the tendon repair site. Further study is required to determine the implications for tendon healing. CLINICAL RELEVANCE Intratendinous blood flow is a variable that should be considered when evaluating repair methods in rotator cuff surgery.

Femoral component revision using an extensively hydroxyapatite-coated stem☆

Femoral component revisions with extensively coated stems have shown promising clinical results, although concerns over stress shielding still exist. We retrospectively reviewed 59 patients undergoing femoral component revision with an extensively hydroxyapatite (HA)-coated stem. The average length of follow-up was 3.3 years (range, 2-5 years). The average preoperative Harris Hip Score was 43 points, which improved to 86 points at the latest follow-up (P < .01). The overall mechanical failure rate was 2%. No evidence of stress shielding was seen in 78% of patients. The clinical results of this series using an extensively HA-coated stem are similar to those using an extensively porous-coated stem. Long-term follow-up is required to determine if an extensively HA-coated implant will be superior to an extensively porous-coated implant with regard to stress shielding.

Optimal entry point for retrograde femoral nailing.

Objective The purpose of this study is to identify the optimum entry point for retrograde femoral nailing, defined as that point which will provide adequate fracture alignment while minimizing soft-tissue and articular cartilage injury. Design Cadaveric study. Setting Biomechanics laboratory. Main Outcome Measure Anatomic relationships and fracture reduction. Methods Eleven cadaveric femori with attached knee joints underwent retrograde femoral nailing with a Synthes femoral nail (Synthes, Paoli, PA, U.S.A.). After placement of the nail, the specimens underwent an osteotomy 3 inches proximal to the articular surface. Multiple entry points were tested to determine fracture alignment and extent of articular cartilage injury. Medial–lateral and anterior–posterior displacements, in addition to any soft-tissue or articular surface trauma, were recorded for these various points of entry. Results An entry point of 1.2 cm anterior to the femoral origin of the posterior cruciate ligament resulted in the least anterior–posterior displacement of the femoral shaft following fracture. In the coronal plane, an entry point at the midpoint of the intercondylar sulcus was identified as minimizing the displacement following fracture. This ideal position allows for proper seating of the nail within the intercondylar sulcus, resulting in minimal damage to the articular cartilage and posterior cruciate ligament and minimal disruption of the patella femoral joint. Conclusion Retrograde femoral nailing should be used cautiously in select patients, when conventional antegrade nailing cannot be used, due to the unavoidable injury to the knee articular surface associated with this technique. The optimum entry point of 1.2 cm anterior to the femoral posterior cruciate ligament origin and centered in the intercondylar sulcus provides the optimal balance of fracture reduction and knee joint sparing. It may be difficult to target this site with a percutaneous technique and may require direct visualization of the intercondylar sulcus for ideal nail placement.

Long Head of the Biceps Tendon Pain: Differential Diagnosis and Treatment

UNLABELLED Though the role of the long head of the biceps tendon (LHBT) in shoulder pathology has been extensively investigated, it remains controversial. Historically, there have been large shifts in opinions on LHBT function, ranging from being a vestigial structure to playing a critical role in shoulder stability. Today, despite incomplete understanding of its clinical or biomechanical involvement, most investigators would agree that LHBT pathology can be a significant cause of anterior shoulder pain. When the biceps tendon is determined to be a significant contributor to a patients symptoms, the treatment options include various conservative interventions and possible surgical procedures, such as tenotomy, transfer, or tenodesis. The ultimate treatment decision is based upon a variety of factors, including the patients overall medical condition, severity, and duration of symptoms, expectations, associated shoulder pathology, and surgeon preference. The purpose of this manuscript is to review current anatomic, functional, and clinical information regarding the LHBT, including conservative treatment, surgical treatment, and postsurgical rehabilitation regimens. LEVEL OF EVIDENCE Level 5.

Treatment of bicondylar tibia plateau fractures using locked plating versus external fixation.

Bicondylar tibial plateau fractures can be difficult to treat due to the extent of articular cartilage, metaphyseal bone, and soft tissue injury. The purpose of this study was to compare the outcomes of open reduction and locked plating vs fine-wire external fixation of 58 consecutive bicondylar tibial plateau fractures at a level I trauma center. All bicondylar tibial plateau fractures were classified as Schatzker V/VI or AO/OTA type 41C. Twenty-eight patients in one group were treated using a locked plating system, and 30 patients in another group were treated with a hybrid or circular external fixation frame. The 2 groups were similar demographically. When compared with external fixation, locked plating was associated with a decreased time to union (5.9 vs 7.4 months), decreased incidence of articular malunion (7% vs 40%; P=.003), decreased knee stiffness (4% vs 13%), and decreased overall complications (27% vs 48%). The Schatzker VI subgroup accounted for 25 of the 27 complications (93%) in the locked plating group and 40 of the 48 complications (83%) in the external fixation group. We reserve the use of external fixation devices in the treatment of tibial plateau fractures to span the fracture site until the patient is amenable to definitive fixation with locked plating.

Comparison of perioperative complications in patients with and without rheumatoid arthritis who receive total elbow replacement

Total elbow replacement is a well-recognized surgical treatment for patients with advanced rheumatoid arthritis (RA) of the elbow. At present, there is minimal literature outlining the perioperative complications associated with total elbow replacement. We endeavored to identify complication rates and hospital disposition differences between patients with and without RA who received a total elbow replacement. Data from the Nationwide Inpatient Sample was used to capture 3,617 patients who received a total elbow arthroplasty between 1988-2005. Of these, 888 had a primary diagnosis of RA and were compared against patients without RA. Analyses addressed perioperative complications and hospital disposition factors, such as charges and length of stay. Overall complication rates were very low with only 2 variables, respiratory complications (P = .01) and renal failure (P = .04) demonstrating significantly worse outcomes in patients without RA (P = .01). Patients without RA had also had longer lengths of stay (P < 0.01). There were 9 reported perioperative deaths. The findings suggest that the perioperative complications of a total elbow replacement for all patients studied are few and that outcomes in patients with RA are nearly equivalent to those in patients without RA.

Whole body, long-axis rotational training improves lower extremity neuromuscular control during single leg lateral drop landing and stabilization.

BACKGROUND Poor neuromuscular control during sports activities is associated with non-contact lower extremity injuries. This study evaluated the efficacy of progressive resistance, whole body, long-axis rotational training to improve lower extremity neuromuscular control during a single leg lateral drop landing and stabilization. METHODS Thirty-six healthy subjects were randomly assigned to either Training or Control groups. Electromyographic, ground reaction force, and kinematic data were collected from three pre-test, post-test trials. Independent sample t-tests with Bonferroni corrections for multiple comparisons were used to compare group mean change differences (P≤0.05/21≤0.0023). FINDINGS Training group gluteus maximus and gluteus medius neuromuscular efficiency improved 35.7% and 31.7%, respectively. Training group composite vertical-anteroposterior-mediolateral ground reaction force stabilization timing occurred 1.35s earlier. Training group knee flexion angle at landing increased by 3.5°. Training group time period between the initial two peak frontal plane knee displacements following landing increased by 0.17s. Training group peak hip and knee flexion velocity were 21.2°/s and 20.1°/s slower, respectively. Time period between the initial two peak frontal plane knee displacements following landing and peak hip flexion velocity mean change differences displayed a strong relationship in the Training group (r(2)=0.77, P=0.0001) suggesting improved dynamic frontal plane knee control as peak hip flexion velocity decreased. INTERPRETATION This study identified electromyographic, kinematic, and ground reaction force evidence that device training improved lower extremity neuromuscular control during single leg lateral drop landing and stabilization. Further studies with other populations are indicated.

Single leg jumping neuromuscular control is improved following whole body, long-axis rotational training

Improved lower extremity neuromuscular control during sports may decrease injury risk. This prospective study evaluated progressive resistance, whole body, long-axis rotational training on the Ground Force 360 device. Our hypothesis was that device training would improve lower extremity neuromuscular control based on previous reports of kinematic, ground reaction force (GRF) or electromyographic (EMG) evidence of safer or more efficient dynamic knee stability during jumping. Thirty-six healthy subjects were randomly assigned to either training (Group 1) or control (Group 2) groups. Using a pre-test, post-test study design data were collected from three SLVJ trials. Unpaired t-tests with adjustments for multiple comparisons were used to evaluate group mean change differences (P≤0.05/25≤0.002). During propulsion Group 1 standardized EMG amplitude mean change differences for gluteus maximus (-21.8% vs. +17.4%), gluteus medius (-28.6% vs. +15.0%), rectus femoris (-27.1% vs. +11.2%), vastus medialis (-20.2% vs. +9.1%), and medial hamstrings (-38.3% vs. +30.3%) differed from Group 2. During landing Group 1 standardized EMG amplitude mean change differences for gluteus maximus (-32.9% vs. +11.1%) and rectus femoris (-33.3% vs. +29.0%) also differed from Group 2. Group 1 peak propulsion vertical GRF (+0.24N/kg vs. -0.46N/kg) and landing GRF stabilization timing (-0.68 vs. +0.05s) mean change differences differed from Group 2. Group 1 mean hip (-16.3 vs. +7.8°/s) and knee (-21.4 vs. +18.5°/s) flexion velocity mean change differences also differed from Group 2. Improved lower extremity neuromuscular efficiency, increased peak propulsive vertical GRF, decreased mean hip and knee flexion velocities during landing, and earlier landing stabilization timing in the training group suggests improved lower extremity neuromuscular control.

Total knee arthroplasty in motivated patients with knee osteoarthritis and athletic activity approach type goals: a conceptual decision-making model

Knee osteoarthritis is one of the most common disabling medical conditions. With longer life expectancy the number of total knee arthroplasty ((TKA)) procedures being performed worldwide is projected to increase dramatically. Patient education, physical activity, bodyweight levels, expectations and goals regarding the ability to continue athletic activity participation are also increasing. For the subset of motivated patients with knee osteoarthritis who have athletic activity approach type goals, early TKA may not be the best knee osteoarthritis treatment option to improve satisfaction, quality of life and outcomes. The purpose of this clinical commentary is to present a conceptual decision-making model designed to improve the knee osteoarthritis treatment intervention outcome for motivated patients with athletic activity approach type goals. The model focuses on improving knee surgeon, patient and rehabilitation clinician dialogue by rank ordering routine activities of daily living and quality of life evoking athletic activities based on knee symptom exacerbation or re-injury risk. This process should help establish realistic patient expectations and goals for a given knee osteoarthritis treatment intervention that will more likely improve self-efficacy, functional independence, satisfaction and outcomes while decreasing the failure risk associated with early TKA.

In situ comparison of varying composite tibial tunnel interference screws used for ACL soft tissue graft fixation

PURPOSE This mechanical study using an in vitro porcine model compared composite interference screw fixation of soft tissue ACL grafts in tibial tunnels. METHODS Forty-eight porcine profundus tendons and tibiae were divided into four groups of 12 closely matched specimens. Equivalent diameter grafts were assigned to each group. Tibial bone tunnels were drilled to 0.5mm greater than graft diameter. Grafts were fixed in tunnels using one 10 × 35 mm composite interference screw designed by four different manufacturers. Maximal insertion torque and perceived within group mechanical testing outcome predictions were recorded. Constructs were potted and loaded into a six degrees of freedom clamp that placed the servohydraulic device tensile loading vector in direct tunnel alignment. Constructs were pre-loaded to 25 N, pre-conditioned between 0 and 50 N for 10 cycles (0.5 Hz), submaximally tested between 50 and 250 N for 500 cycles (one hertz) and load to failure tested at 20mm/min. RESULTS Statistically significant differences were not observed between groups for displacement during submaximal cyclic loading, yield load, displacement at yield load, stiffness, ultimate load at failure and displacement at ultimate load. One composite screw group displayed a slightly greater proportion of specimens that required use of more than one screw during insertion. CONCLUSIONS Under highly controlled conditions groups displayed comparable fixation.