Brian A. Klatt

Tunnel expansion following anterior cruciate ligament reconstruction: a comparison of hamstring and patellar tendon autografts

Abstract Thirty patients having had anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BPTB) autograft and thirty patients having had ACL reconstruction with hamstring (HS) autograft were enrolled. All procedures were performed using an endoscopic technique with identical postoperative rehabilitation, such that the only variable was the type of graft and its fixation. Lateral and 45° posteroanterior (PA) weightbearing radiographs were performed in each patient at 6–12 (mean 9) months postoperatively in the HS group and 9–22 (mean 13) months postoperatively in the PT group. The sclerotic margins of the tunnel were measured at the widest dimension of the tunnel by a single observer and were compared with the initially drilled tunnel size after correction for radiographic magnification. For the BPTB group, all bone plugs appeared to be incorporated radiographically. On the femoral side, the bone plug was incorporated at the roof of the intercondylar notch, such that no tunnel measurement could be made. Well-defined sclerotic margins were always present at the tibial and femoral tunnels for the HS group and at the tibial tunnel for the BPTB group. The mean percentage increase in tunnel size in the PA view was 9.7% ± 14.7% for the BPTB tibial tunnel, 20.9% ± 13.4% for the HS tibial tunnel, and 30.2% ± 17.2% for the HS femoral tunnel. The mean percentage increase in tunnel size in the lateral view was 14.4% ± 16.1% for the BPTB tibial tunnel, 25.5% ± 16.7% for the HS tibial tunnel, and 28.1% ± 14.7% for the HS femoral tunnel. The difference in HS and BPTB tibial tunnel expansion on both the PA and lateral views was statistically significant (P = 0.003 and P = 0.01, respectively). Inter-observer variability was excellent with an intra-class correlation coefficient of 0.92. Tunnel expansion was significantly greater following ACL reconstruction using HS autografts than in those using BPTB autografts. The points of fixation for the HS grafts are at a greater distance from the normal insertion site and biomechanical point of action of the ACL than the points of fixation for BPTB grafts. We believe that this greater distance creates a potentially larger force moment during graft cycling which may lead to greater expansion of bone tunnels.

Preoperative Decolonization Effective at Reducing Staphylococcal Colonization in Total Joint Arthroplasty Patients

Staphylococcus decolonization prior to surgery is used to prevent surgical site infections (SSIs) after total joint arthroplasty (TJA). To determine if current treatment protocols result in successful decolonization of methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA), 106 consecutive patients were screened for nasal MSSA/MRSA colonization pre-operatively and on the day of surgery. Colonized patients used intranasal mupirocin twice a day and chlorhexidine showers daily 5 days prior to surgery. Pre-operatively, 24 joints (22.0%) were positive for MSSA colonization and 5 joints (4.6%) were positive for MRSA colonization. On the day of surgery, 3 joints (2.8%) who underwent decolonization were positive for MSSA colonization and 0 joints were positive for MRSA colonization. The reduction in MSSA colonization was significant (P<0.001), while the eradication of MRSA colonization approached statistical significance (P=0.063). Current decolonization protocols using intranasal mupirocin and chlorhexidine washes are effective for reducing MRSA/MSSA colonization.

Exchange reamed nailing for aseptic nonunion of the tibia.

BACKGROUND Exchange reamed nailing of the tibia is a common procedure in the treatment of an aseptic tibial nonunion. However, reports in the literature supporting this technique are limited. METHODS Forty patients with a tibial nonunion after initial unreamed intramedullary nailing were retrospectively assessed after an exchange reamed nailing. The main outcome measurements included radiographic and clinical union as well as time from exchange reamed nailing to union. RESULTS Thirty-eight patients achieved union of their fracture (95%). The average time from exchange nailing to union was 29 +/- 21 weeks. Complications included one deep vein thrombosis (2.5%) and two hardware failures (5%). CONCLUSION Exchange reamed nailing for nonunions of the tibia results in a high union rate and is associated with a low complication rate. This technique is recommended as a standard procedure for aseptic tibial nonunions after initial unreamed intramedullary nailing.

Model-Based Tracking of the Hip: Implications for Novel Analyses of Hip Pathology

This study investigated the efficacy of a combined high-speed, biplane radiography and model-based tracking technique to study hip joint kinematics and arthrokinematics. Comparing model-based tracking to the gold standard of radiostereometric analysis using implanted metal beads, joint translation was measured with a bias of 0.2 mm and a precision of 0.3 mm, whereas joint rotation was measured with a bias of 0.2° and a precision of 0.8°. A novel measure of hip arthrokinematics characterizing the region of closest contact in the anterosuperior acetabulum was measured with a bias of 0.9% and a precision of 2.5%. Model-based tracking of the hip thus provides the opportunity to noninvasively study hip pathologic conditions such as osteoarthritis and femoroacetabular impingement with great accuracy.

Better function for fusions versus above-the-knee amputations for recurrent periprosthetic knee infection.

BackgroundTreatment of chronic periprosthetic joint infections (PJIs) after TKA is limited to fusions, above-the-knee amputations (AKAs), revision TKA, and antibiotic suppression and is often based on the patient’s medical condition. However, when both fusion and AKA are options, it is important to compare these two procedures with regard to function.Questions/purposesDo patients receiving a knee fusion for PJI after TKA have better function compared to patients receiving an AKA?MethodsWe retrospectively reviewed patients who were eligible for either fusion or AKA after PJI TKA. Thirty-seven patients underwent a fusion for PJIs after TKA between 1999 and 2010. Nine patients died postoperatively and eight patients were lost to followup, leaving 20 patients. Patients completed a specialized questionnaire about their fusion, and functional capability was assessed by the SF-12. We compared fusions to a previously published group of six patients who underwent AKA for recurrent PJI after TKA.ResultsFor patients with fusion, community ambulators increased from five to 10 and nonambulators decreased from three to one. For patients with AKA, nonambulatory patients increased from zero to two, and community ambulators decreased from four to one. The SF-12 physical component summary measurements were higher for fusions (51) than for AKAs (26). The mental component summary was also higher in fusions (60) than in AKAs (44). Seventy percent of patients indicated they would undergo a fusion again instead of undergoing an amputation if they were presented with both options after undergoing their operation.ConclusionsPatients receiving knee fusions for treating recurrent PJIs after TKA have better function and ambulatory status compared to patients receiving AKA.Level of EvidenceLevel III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Facilitation or Inhibition of the Estradiol‐Induced Gonadotropin Surge in the Immature Rat by Progesterone: Regulation of GnRH and LH Messenger RNAs and Activation of GnRH Neurons

We have developed and extensively characterized immature female rat models to demonstrate inhibition or facilitation of the estradiol (E2)‐induced gonadotropin surge by progesterone (P). We show here that the surge of free α‐subunit is regulated similarly by P in these models. To investigate the possibility that P alters the biosynthesis of GnRH and/or LH, we measured levels of LH subunit mRNAs by Northern blot hybridization and GnRH mRNA by a solution hybridization‐RNase protection assay. In the P inhibition model, α‐subunit mRNA was significantly decreased when P was administered together with E2 for 32 or 48 h, and LHβ, at 29 h. In the facilitation model, neither α‐subunit nor LHβ mRNA increased with premature and enhanced release of LH and free α‐subunit. Levels of GnRH mRNA in E2‐treated rats were significantly higher on the afternoon of the LH surge than on that or the following morning. There was no effect of P on GnRH mRNA levels, however, before, during, or after the LH surge in either paradigm. The time course of activation of GnRH neurons in P‐facilitated rats was determined by double‐label immunocytochemistry for GnRH and cFos. When serum LH concentrations were basal there was no expression of cFos in GnRH neurons. LH secretion in P‐facilitated rats was initiated at ≈14.00 h and remained elevated until at least 19.00 h. During this time 63–78% of GnRH neurons were cFos positive. Both serum LH concentrations and the percentage of cFos‐activated GnRH neurons were significantly lower in control rats treated with E2 alone than in those treated also with P. In conclusion: 1) suppression of LH and free α‐subunit secretion by P can be accounted for at least partly by suppression of α‐subunit mRNA levels; 2) P facilitation is not associated with changes in LH subunit or GnRH mRNA levels; 3) the large proportion of cFos‐positive GnRH neurons in P‐facilitated rats closely parallels increases in serum LH concentrations but is not accompanied by changes in GnRH mRNA levels. It is likely, therefore, that P acts in the facilitation model to trigger release of pre‐existing GnRH stores by altering synthesis or activity of neuro‐transmitters/neuropeptides involved in GnRH regulation and/or release of LH stores by altering, for example, pituitary responsiveness to GnRH (including self‐priming) and components of the LH secretory apparatus. Similar possibilities may also obtain for the blockade of the gonadotropin surge in the inhibition model.

Effect of immediate postoperative physical therapy on length of stay for total joint arthroplasty patients.

The isolated effect of physical therapy (PT) on total joint arthroplasty hospital length of stay (LOS) has not been studied. A prospective cohort study was conducted on 136 primary total joint arthroplasties (58 hips, 78 knees). The LOS was determined by the operative start time until the time of discharge. On postoperative day (POD) 0, 60 joints remained in bed, 51 moved to a chair, and 25 received PT (22 ambulated, 3 moved to a chair). Length of stay differed for patients receiving PT on POD 0 (2.8 ± 0.8 days) compared with POD 1 (3.7 ± 1.8 days) (P = .02). There was no difference in PT treatment based on nausea/vomiting, pain levels, or discharge location. Isolated PT intervention on POD 0 shortened hospital LOS, regardless of the intervention performed.

Altered tibiofemoral joint contact mechanics and kinematics in patients with knee osteoarthritis and episodic complaints of joint instability

BACKGROUND To evaluate knee joint contact mechanics and kinematics during the loading response phase of downhill gait in knee osteoarthritis patients with self-reported instability. METHODS Forty-three subjects, 11 with medial compartment knee osteoarthritis and self-reported instability (unstable), 7 with medial compartment knee osteoarthritis but no reports of instability (stable), and 25 without knee osteoarthritis or instability (control) underwent Dynamic Stereo X-ray analysis during a downhill gait task on a treadmill. FINDINGS The medial compartment contact point excursions were longer in the unstable group compared to the stable (P=0.046) and the control groups (P=0.016). The peak medial compartment contact point velocity was also greater for the unstable group compared to the stable (P=0.047) and control groups (P=0.022). Additionally, the unstable group demonstrated a coupled movement pattern of knee extension and external rotation after heel contact which was different than the coupled motion of knee flexion and internal rotation demonstrated by stable and control groups. INTERPRETATION Our findings suggest that knee joint contact mechanics and kinematics are altered during the loading response phase of downhill gait in knee osteoarthritis patients with self-reported instability. The observed longer medial compartment contact point excursions and higher velocities represent objective signs of mechanical instability that may place the arthritic knee joint at increased risk for disease progression. Further research is indicated to explore the clinical relevance of altered contact mechanics and kinematics during other common daily activities and to assess the efficacy of rehabilitation programs to improve altered joint biomechanics in knee osteoarthritis patients with self-reported instability.

Blood Utilization After Primary Total Joint Arthroplasty in a Large Hospital Network

BackgroundSince a study in orthopedic hip fracture patients demonstrated that a liberal hemoglobin (Hb) threshold does not improve patient morbidity and mortality relative to a restrictive Hb threshold, the standard of care in total joint arthroplasty (TJA) should be examined to understand the variability of red blood cell (RBC) transfusion following TJA.Questions/purposesThe study aimed to answer the following questions: (1) What is the blood utilization rate after primary TJA for individual surgeons within a large hospital network? (2) What is the comparison of hospital charges, length of stay (LOS), and discharge locations among TJA patients who were and were not transfused?MethodsA retrospective study was conducted on 3,750 primary total knee arthroplasties (TKAs) and 2,070 primary total hip arthroplasties (THAs), and data was retrospectively collected over a 15-month period on the number of RBCs transfused per patient, along with demographic and cost details. The number of patients who received at least 1 RBC unit and the number of RBCs transfused per patient was calculated and stratified by surgeon.ResultsIn the postoperative period, 19.3% TKA patients and 38.5% THA patients received a RBC transfusion. Transfusion rates following TJA varied widely between surgeons (TKA 4.8–63.8%, THA 4.3–86.8%). Transfused TKA patients received an average of 1.65 ± 0.03 RBCs, and THA patients received an average of 1.97 ± 0.14 RBCs. LOS and hospital charges for blood transfusion patients were higher than nontransfused patients.ConclusionBlood utilization after primary TJA varies greatly among surgeons, suggesting that resources may be misallocated. These findings highlight the need to standardize RBC transfusion practice following TJA.

Are the kinematics of the knee joint altered during the loading response phase of gait in individuals with concurrent knee osteoarthritis and complaints of joint instability? A dynamic stereo X-ray study

BACKGROUND Joint instability has been suggested as a risk factor for knee osteoarthritis and a cause of significant functional decline in those with symptomatic disease. However, the relationship between altered knee joint mechanics and self-reports of instability in individuals with knee osteoarthritis remains unclear. METHODS Fourteen subjects with knee osteoarthritis and complaints of joint instability and 12 control volunteers with no history of knee disease were recruited for this study. Dynamic stereo X-ray technology was used to assess the three-dimensional kinematics of the knee joint during the loading response phase of gait. FINDINGS Individuals with concurrent knee osteoarthritis and joint instability demonstrated significantly reduced flexion and internal/external rotation knee motion excursions during the loading response phase of gait (P<0.01), while the total abduction/adduction range of motion was increased (P<0.05). In addition, the coronal and transverse plane alignment of the knee joint at initial contact was significantly different (P<0.05) for individuals with concurrent knee osteoarthritis and joint instability. However, the anteroposterior and mediolateral tibiofemoral joint positions at initial contact and the corresponding total joint translations were similar between groups during the loading phase of gait. INTERPRETATIONS The rotational patterns of tibiofemoral joint motion and joint alignments reported for individuals with concurrent knee osteoarthritis and joint instability are consistent with those previously established for individuals with knee osteoarthritis. Furthermore, the findings of similar translatory tibiofemoral motion between groups suggest that self-reports of episodic joint instability in individuals with knee osteoarthritis may not necessarily be associated with adaptive alterations in joint arthrokinematics.