Robotic guidance does not improve component position or short-term outcome in medial unicompartmental knee arthroplasty.

We performed a retrospective review in a matched group of patients on the use of robotic-assisted UKA implantation versus UKA performed using standard operative techniques to assess differences between procedures. While both techniques resulted in reproducible and excellent outcomes with low complication rates, the results demonstrate little to no clinical or radiographic difference in outcomes between cohorts. Average operative time differed significantly with, and average of 20 minutes greater in, the robotic-assisted UKA group (P=0.010). Our minimal clinical and radiographic differences lend to the argument that it is difficult to justify the routine use of expensive robotic techniques for standard medial UKA surgery, especially in a well-trained, high-volume surgeon. Further surgical, clinical and economical study of this technology is necessary.

Use of bovine thrombin to reduce blood loss in primary total knee arthroplasty: a controlled randomized trial.

Reducing blood loss during primary total knee arthroplasty (TKA) can improve outcomes by reducing transfusion requirements and wound complications. We examined the use of bovine thrombin to augment hemostasis during primary TKA. A double-blinded randomized trial was performed with 80 primary TKA patients. Half received intraarticular bovine thrombin at the time of wound closure, and half did not. Hemoglobin levels in the study group did decline less than the control group, but no statistically significant difference was found in rates of transfusion, drain outputs, length of stay, or Knee Society scores. This agent does appear to slightly reduce blood loss, but routine use is not cost effective. Thrombin may be considered for patients who would benefit more from greater blood conservation.

What is the role of serological testing between stages of two-stage reconstruction of the infected prosthetic knee?

BACKGROUND: Two-stage exchange arthroplasty is the gold standard for treatment of infected TKA. The erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and synovial fluid white blood cell (WBC) count with differential are often used to determine treatment response; however, it is unclear whether these tests can answer the critical question of whether joint sepsis has been controlled between stages and if reimplantation is indicated. QUESTIONS/PURPOSES: We therefore asked if (1) these serologies respond between stage one explantation and stage two reimplantation during two-stage knee reconstruction for infection; and (2) changes in the values of these serologies are predictive of resolution of joint infection. METHODS: We retrospectively reviewed the serologies of 76 infected patients treated with a two-stage exchange protocol. The ESR, CRP, and aspiration were repeated a minimum of 2 weeks following antibiotic cessation and prior to second stage reoperation. Comparisons were made to identify trends in these serologies between the first and second stage procedures. RESULTS: Eight knees (12%) were persistently infected at the time of second stage reoperation. The ESR remained persistently elevated in 37 knees (54%), and the CRP remained elevated in 14 knees (21%) where infection had been controlled. We were unable to identify an optimum cutoff value for the ESR, CRP, or the two combined. The best test for confirmation of infection control was the synovial fluid WBC count. CONCLUSIONS: Although the ESR, CRP, and synovial fluid WBC counts decreased in cases of infection control, these values frequently remained elevated. We were unable to identify any patterns in these tests indicative of persistent infection. LEVEL OF EVIDENCE: Level II, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Gap balancing through small incisions: competing goals.

Significant controversy exists in the literature regarding the pitfalls and benefits of minimally invasive total knee arthroplasty (TKA). Regardless, most surgeons today use smaller exposures than in previous years. Although more difficult, rigid adherence to classical gap balancing techniques can allow a surgeon to achieve ideal ligament and flexion/extension gap balance in TKA through a minimally invasive approach. There are certain groups of patients (obesity/medical comorbidities/vascular insufficiency) in whom small incision approaches should not be attempted due to increased risks of wound complications. Additionally, achievement of gap balance requires sequential and safe removal of bone starting with the patellar cut, followed by the distal femoral cut, then by the tibial cut, and concluding with completion of the femoral component cuts. Use of special instruments such as protective metal patellar buttons, medial to lateral distal femoral cutting blocks, and low profile spacer blocks can facilitate the surgical process. Accurate femoral component rotation is more difficult in minimally invasive approaches and must be carefully checked. A tight extensor mechanism in flexion can mislead the surgeon to place the femoral component in an internally rotated position. Furthermore, with limited visualization, surgeons must avoid overaggressive ligament releases early in the procedure prior to completion of bone cuts. However, with appropriate patient selection and a systematic approach to minimally invasive total knee arthroplasty, surgeons can continue to achieve ideal ligament balance with a more soft tissue friendly operation.

The feasibility and perioperative complications of outpatient knee arthroplasty.

UNLABELLED: The duration of hospitalization and subsequent length of recovery after elective knee arthroplasty have decreased. We hypothesized same-day discharge following either a unicompartmental (UKA) or total knee arthroplasty (TKA) in an unselected group of patients would not result in a higher perioperative complication rate than standard-length hospitalization when following a comprehensive perioperative clinical pathway, including preoperative teaching, regional anesthesia, preemptive oral analgesia, preemptive antiemetics, and a rapid rehabilitation protocol. We prospectively followed 111 of all 121 patients who had primary knee arthroplasty completed by noon and who agreed to be followed prospectively; 25 had UKA and 86 TKA. Of the 111 patients, 104 (94%, 24 with UKA and 80 with TKA) met discharge criteria and were discharged directly to home the day of surgery. Nausea requiring additional treatment before discharge was the most common reason for a delay in discharge. There were four (3.6%) readmissions (all with TKA) and one emergency room visit without readmission (in a patient with a TKA) within the first week after surgery, while there were four subsequent readmissions (3.6%) and one additional emergency room visit without readmission within three months of surgery, all among patients undergoing TKA. There were no deaths, cardiac events, or pulmonary complications during this study. Outpatient knee arthroplasty surgery is feasible in a large percentage of patients yet early readmissions may be decreased with a prolonged hospitalization. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Lateral retinacular release during primary total knee arthroplasty: effect on outcomes and complications.

Intraoperative lateral retinacular release performed during primary total knee arthroplasty (TKA) can improve patellar tracking. This study compares the outcomes of patients who did and did not have lateral retinacular release during primary TKA. One thousand one hundred eight consecutive primary TKAs were reviewed. Lateral release was performed on 314 patients; 794 patients did not undergo release. Comparisons of range of motion, Knee Society Score, and postoperative complications were made between the 2 groups. At an average follow-up of 4.7 years, no statistically significant difference in range of motion, Knee Society Score, or postoperative complications of patella fracture, subluxation, postoperative manipulation, or wound complications was demonstrated. Lateral retinacular release to achieve improved patellar tracking does not compromise the clinical outcomes or complication rate of primary TKA.

Spinal cord dimensions in children with Klippel-Feil syndrome: a controlled, blinded radiographic analysis with implications for neurologic outcomes.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To evaluate the axial cross-sectional dimensions of the spinal cord and cerebrospinal fluid (CSF) column in children with Klippel-Feil Syndrome (KFS) versus an age-matched cohort of control subjects. SUMMARY OF BACKGROUND DATA: Neurologic sequelae and chronic pain are known to occur in KFS and factors implicated include spinal cord compression from canal stenosis, segmental instability, vascular disruption, and central nervous system abnormalities including tethered cord, syrinx, and diastomyelia. No study to date, however, has examined the role of spinal cord size as a contributing factor to neurologic sequelae in KFS. METHODS: We retrospectively reviewed the plain radiographic, magnetic resonance imaging (MRI), and clinical records of 12 consecutive patients between 2 and 18 years with KFS (average age 9.5 +/- 5.3 years) and 14 age-matched controls (average age 8.3 +/- 5.1 year). For each patient, plain film radiography was reviewed to compare Torg ratios at each cervical level, and axial T1-weighted MRI was used to compare spinal cord and CSF column cross-sectional area calculations. RESULTS: The Torg-Pavlov ratios were identical between the 2 groups (0.77 +/- 0.15 vs. 0.77 +/- 0.19). Analysis of axial T1-weighted MRI cross-sectional spinal cord area revealed that the cord was smaller in KFS patients at each level from C2-C7 compared with controls. These differences were statistically significant at C4 (P = 0.016), C5 (P = 0.035), and C6 (P = 0.032). Subset analysis of abnormal (fused) levels compared with controls revealed the same findings, although these differences were not significant due to the limited numbers available at each level. Analysis of the CSF column, however, revealed that overall the canal was slightly larger in KFS patients compared with controls, although this difference was not statistically significant. Four of the 12 KFS patients presented with neurologic symptoms, all of which improved after posterior cervical stabilization. CONCLUSION: In our cohort of patients we have noted statistically significant differences in axial cord dimensions, with no differences in CSF column, suggesting that the cord size is smaller in KFS children compared with age-matched controls.

Measuring the attitudes and impact of the eighty-hour workweek rules on orthopaedic surgery residents.

BACKGROUND: The literature on graduate medical education contains anecdotal reports of some effects of the new eighty-hour workweek on the attitudes and performance of residents. However, there are relatively few studies detailing the attitudes of large numbers of residents in a particular surgical specialty toward the new requirements. METHODS: Between July and November 2004, a survey created by the Academic Advocacy Committee of the American Academy of Orthopaedic Surgeons was distributed by mail, fax, and e-mail to a total of 4207 orthopaedic residents at the postgraduate year-1 through year-6 levels of training. The survey responses were tabulated electronically, and the results were recorded. RESULTS: The survey response rate was 13.2% (554 residents). Sixty-eight percent (337) of the 495 respondents whose postgraduate-year level was known were at the postgraduate year-4 level or higher. Attitudes concerning the duty rules were mixed. Twenty-three percent of the 554 respondents thought that eighty hours constituted an appropriate number of duty hours per week; 41% believed that eighty hours were too many, and 34% thought that eighty hours were not sufficient. Thirty-three percent of the respondents had worked greater than eighty hours during at least a single one-week period since the new rules were implemented; this occurred more commonly among the postgraduate year-3 and more junior residents. Orthopaedic trauma residents had the most difficulty adhering to the new duty-hour restrictions. Eighty-two percent of the respondents indicated that their residency programs have been forced to make changes to their call schedules or to hire ancillary staff to address the rules. The use of physician assistants, night-float systems, and so-called home-call assignments were the most common strategies used to achieve compliance. CONCLUSION: Resident attitudes toward the work rules are mixed. The rules have forced residency programs to restructure. Junior residents have more favorable attitudes toward the new standards than do senior residents. Self-reporting of duty hours is the most common method of monitoring in orthopaedic training programs. Such systems allow ample opportunity for inaccuracies in the measurement of hours worked. Although residents report an improved quality of life as a result of these new rules, the attitude that the quality of training is diminished persists.