Cannabinoid and Opioid Use Among Total Joint Arthroplasty Patients: A 6-Year, Single-Institution Study.

Evidence is limited regarding cannabinoid use among total joint arthroplasty (TJA) patients, despite increased availability and popularity for treating chronic pain. The authors hypothesized that preoperative cannabinoid use increased and opioid use decreased during a 6-year interval in total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients, and also asked whether complications were associated with use of these substances. This retrospective, single-institution study reviewed electronic medical records and the Veterans Affairs Surgical Quality Improvement Program (VASQIP) database for TJA cases from 2012 through 2017. Primary outcomes were the prevalence and trends of active cannabinoid and opioid use, as determined by routine preoperative urine toxicology screening. Multivariable regression analyses were conducted to investigate a secondary outcome, whether there was an association between cannabinoid or opioid use and postoperative complications. A total of 1778 operations (1161 TKAs and 617 THAs) performed on 1519 patients were reviewed. The overall prevalence of pre-operative cannabinoid and opioid use was 11% and 23%, respectively. Comparing 2012 with 2017, cannabinoid use increased from 9% to 15% (P=.049), and opioid use decreased from 24% to 17% (P=.040). Cannabinoid users were more likely to be taking opioids than nonusers (P=.002). Controlling for age, sex, surgery type, and American Society of Anesthesiologists score, cannabinoid use was not associated with 90-day readmission, infection, reoperation, or other VASQIP-captured complications. Laboratory testing indicated a much higher prevalence of cannabinoid use among TJA patients than previously reported. During a 6-year period, cannabinoid use increased more than 60%, and opioid use decreased approximately 30%. These findings indicate that cannabinoid use did not appear to be associated with perioperative complications. [Orthopedics. 2021;44(1):e101-e106.].

A survey of Hip Society surgeons concerning the direct anterior approach total hip arthroplasty.

AIMS: To establish whether there was a consensus among the members of the Hip Society (HS) on the role of direct anterior approach (DAA) contemporary primary total hip arthroplasty (THA). METHODS: An online survey was sent to all 112 active and senior members of the HS, to which 71 members responded. The survey was constructed to determine whether they believed that evidence-based medicine proves, in modern clinical practice, that the DAA has significant benefits compared to risks when contrasted with other approaches. In addition, they were asked if they currently used the DAA. RESULTS: While only 16.9% (12/71) of respondents had been trained in a generic anterior approach during residency, 49.3% (35/71) had used the DAA in their clinical practice in the past or were using it at the present time. Unexpectedly, 42.9% (15/35) of respondents who had used the DAA in the past had abandoned it by the time of this survey. Only 22.5% (16/71) of all respondents believed that evidence-based medicine proves that the DAA has significant benefits compared to risks in contrast to other approaches. CONCLUSION: A comprehensive literature review found only three prospective randomized clinical trials (RCT) comparing the DAA with another approach with greater than one-year follow-up. Two showed minor benefits within the early postoperative period only, and one of those showed poorer mid-term results. Most of the published comparison studies with short follow-up show longer surgical times and greater blood loss for the DAA, and many three-month comparison studies show higher complication rates for the DAA using a proprietary traction table. The complications included problems with wound healing, lateral femoral cutaneous nerve injury, femoral component loosening, and femoral fractures. Because of the lack of evidence from RCTs showing superiority of the DAA over other approaches and reports of higher complications, the opinion of a large majority (77.5%; 55/71) of HS surgeons was that the DAA lacks sufficient evidence to warrant its use. Cite this article: Bone Joint J 2020;102-B(7 Supple B):57-61.

Mobile Compression Reduces Bleeding-related Readmissions and Wound Complications After THA and TKA.

BACKGROUND: The use of chemoprophylaxis to prevent thromboembolic disease after primary THA and TKA can be associated with postoperative bleeding complications. Mechanical prophylaxis has been studied as an alternative to chemoprophylaxis with greater safety in patients undergoing THA, but no data have been published comparing the safety of chemoprophylaxis versus mechanical methods for patients undergoing TKA. The risk of readmission resulting from bleeding and venous thromboembolism (VTE) has also not been determined for patients undergoing THA or TKA when treated with low-molecular-weight heparin (LMWH) alone compared with mechanical prophylaxis plus aspirin (ASA). QUESTION/PURPOSES: We sought to answer four questions: For the THA and TKA cohorts, respectively, (1) was the incidence of readmission resulting from VTE and bleeding complications higher with LMWH than mobile compression plus ASA; and (2) was the incidence of wound bleeding complications higher with LMWH than mechanical compression plus ASA? For the TKA cohort specifically, (3) was the frequency of systemic bleeding events and complications related to chemical prophylaxis higher with LMWH compared with mechanical compression plus ASA? (4) Was there a difference in symptomatic VTEs between LMWH and mechanical compression plus ASA? METHODS: Between November 2008 and April 2011, 632 patients underwent primary THA and TKA. Seventy-two patients (11%) were identified before surgery as being at high risk for VTE (31 patients) or bleeding (41 patients) and were excluded from the study. Five hundred sixty patients (89%) were considered to be at standard risk for VTE and bleeding and comprise the study cohort. Between November 2008 and November 2009, 252 patients (76 THAs, 176 TKAs) underwent THA and TKA and were treated with LMWH (5 mg dalteparin given subcutaneously daily for 14 days) and in-hospital nonmobile mechanical compression. Between November 2009 and April 2011, a total of 308 patients undergoing THA and TKA (108 THAs, 200 TKAs) were treated using a mobile compression device plus oral aspirin once daily for 2 weeks after surgery. All complications and readmissions that occurred within 6 weeks of surgery were noted. There were no differences between the VTE treatment groups with regard to age, sex, or body mass index. RESULTS: For the THA cohort, there was no difference in the frequency of readmission for a bleeding complication (wound or systemic) between the two groups (2.6% for LMWH versus 0.9% for mobile compression; p = 0.57; odds ratio [OR], 2.9). Patients undergoing TKA treated with LMWH had higher readmission rates within 6 weeks of surgery because of a bleeding complication, a wound infection, or the development of a VTE (6.8% for LMWH versus 1.5% for mobile compression; p = 0.015; OR, 4.8). For the THA cohort, there was higher wound bleeding complication frequency with LMWH (9.2% for LMWH versus 0.9% for mechanical compression; p = 0.009; OR, 10.9). Patients undergoing TKA treated with LMWH had a higher frequency of wound bleeding complications or infection (3.9% for LMWH versus 0.5% for mobile compression; p = 0.028; OR, 8.2). Patients undergoing TKA treated with LMWH had higher rates of systemic bleeding or a complication secondary to LMWH administration (2.8% for LMWH versus 0% for mobile compression; p = 0.022; OR, 12.8). No difference was noted in the rate of symptomatic VTEs between either group (for THA: 2.6% for the LMWH group versus 1.9% for the mechanical compression group; p = 1; for TKA: 1.1% versus 0%, respectively; p = 0.22). CONCLUSIONS: Based on these results, we advocate for routine use of mobile mechanical compression devices in the prevention of VTEs and complications associated with more potent chemical anticoagulants. However, more focused randomized clinical trials are needed to validate these findings. LEVEL OF EVIDENCE: Level III, therapeutic study.

History of Nocturia May Guide Urinary Catheterization for Total Joint Arthroplasty.

Urinary tract infection is a common complication after total knee arthroplasty (TKA) and can be related to urethral catheterization. This study attempted to determine whether nocturia could be used as an indicator of risk for postoperative urinary retention to limit the need for prophylactic catheterization in men undergoing TKA. A retrospective study was performed in a consecutive series of men undergoing TKA at a single Veterans Affairs medical center. Patients reporting 0 episodes or 1 episode of nocturia per night were not catheterized prophylactically, and patients reporting 2 or more episodes of nocturia each night were catheterized preoperatively. Of 100 consecutive patients, 51 reported no more than 1 episode of nocturia and did not undergo preoperative catheterization. Of these patients, 10 required 1 postoperative straight catheterization for urinary retention. In the 49 patients who were catheterized prophylactically, all catheters were removed on postoperative day 1. Only 1 of these patients required reinsertion of a catheter. No patient in either group was discharged with a catheter or had a urinary tract infection. Previously, the authors' standard protocol was to use a prophylactic urinary catheter for all men after TKA. In this 100-patient cohort, with this new protocol, 41 patients were not catheterized at all and 10 patients had only 1 straight catheterization. In this study, the frequency of nocturia in men undergoing TKA was an effective screening tool that safely reduced the need for an indwelling catheter in 51% of patients. [Orthopedics. 2016; 39(4):e749-e752.].

How do I get out of this jam? Early postoperative problems of primary total hip arthroplasty.

Acute postoperative problems associated with total hip arthroplasty typically require prompt attention. Because the circumstances surrounding these problems provide limited time for consultation or literature review, effective management depends on the surgeon being aware of treatment options and favored treatment methods and executing the best treatments. Surgeons should be aware of management strategies for the most common and difficult early postoperative complications after primary total hip arthroplasty, including wound problems, periprosthetic femur fractures, nerve dysfunction, and venous thromboembolism. State-of-the-art knowledge will help the treating surgeon successfully manage complications.

Component alignment during total knee arthroplasty with use of standard or custom instrumentation: a randomized clinical trial using computed tomography for postoperative alignment measurement.

BACKGROUND: Patient-specific femoral and tibial cutting blocks produced with use of data from preoperative computed tomography (CT) or magnetic resonance imaging (MRI) scans have been employed recently to optimize component alignment in total knee arthroplasty. We report the results of a randomized controlled trial in which CT scans were used to compare postoperative component alignment between patients treated with custom instruments and those managed with traditional instruments. METHODS: The in-hospital data and early clinical outcomes, including Knee Society scores, were determined in a randomized clinical trial of forty-seven patients who had undergone a total of forty-eight primary total knee arthroplasties with patient-specific instruments (twenty-two knees) or standard instruments (twenty-six knees). Orientation of the implants was compared by using three-dimensional CT data. RESULTS: No significant differences were found between the study and control groups with respect to any clinical outcome after a minimum of six months of follow-up. The patient-specific tibial cutting block was abandoned in favor of a standard external alignment jig in seven of the twenty-two study knees because of possible malalignment. A detailed analysis of intent-to-treat and per-protocol groups of study and control knees did not show any significant improvement in component alignment, including femoral component rotation in the axial plane, in the patients treated with the custom instruments. The percentage of outliers--defined as less than -3° or more than 3° from the correct orientation of the tibial slope--was significantly higher in the group treated with use of patient-specific blocks than it was in the control group, in both the intent-to-treat (32% versus 8%, p = 0.032) and the per-protocol (47% versus 6%, p = 0.0008) analysis. CONCLUSIONS: There were no significant improvements in clinical outcomes or knee component alignment in patients treated with patient-specific cutting blocks as compared with those treated with standard instruments. The group treated with patient-specific cutting blocks had a significantly higher prevalence of malalignment in terms of tibial component slope than the knees treated with standard instruments.

MI TKA: a risk factor for early revision surgery.

Minimal incision total knee arthroplasty (MI TKA) was developed with the potential to decrease surgical trauma, pain, and recovery time. While this procedure has increased in popularity, some surgeons have questioned its safety and long-term efficacy. In this study 58 consecutive revision total knee arthroplasties (TKAs) (57 patients) performed at one academic medical center from 2006 to 2008 are reviewed. Prospectively collected clinical and radiographic data included: incision length, gender, age, time to revision surgery, and primary diagnosis at time of revision. Of these, 34 knees involving infection and rerevision were excluded. Of the remaining 24 knees, 11 knees that met inclusion criteria had undergone MI TKA. There were no differences between the groups with regard to age, diagnosis, body mass index, and gender. Average time to revision was shorter for the MI TKA patients (29 vs. 65 months, p < 0.032, odds ratio 14.7). Reasons for revision were aseptic loosening (55%), pain/stiffness (27%), malrotation (9%), and instability (9%) in the MI TKA group and aseptic loosening (53%), instability (15%), pain/stiffness (8%), malrotation (8%), combined malrotation and instability (8%), and polyethylene wear/osteolysis (8%) in the traditional TKA group. These data suggest that MI TKA may be a risk factor for early revision.

Long-term comparison of mobile-bearing vs fixed-bearing total knee arthroplasty.

Few published reports have been published regarding a comparison of the long-term outcomes between mobile- (MB) and fixed-bearing component designs for knee arthroplasty. The minimum 10-year clinical and radiologic follow-up of an unselected consecutive series of 89 patients (107 knees) who were randomized to have one of these different designs for primary arthroplasty was done. Twenty-six patients (30 knees) who had a fixed-bearing design and 24 patients (33 knees) who had an MB prosthesis were available for follow-up. Two MB knees were revised for aseptic loosening of a tibial component in one and femoral component fracture in the other. In patients who did not have revision surgery, there were no differences between the groups with respect to mean Knee Society scores, knee flexion, or pain scores.

Local infiltration analgesia in TKA patients reduces length of stay and postoperative pain scores.

Numerous postoperative pain protocols exist for patients undergoing total knee arthroplasty (TKA). We compared the length of stay, early range of motion (ROM), and pain scores of a control group with a femoral nerve block to those of a group with femoral nerve block and local infiltration analgesia following TKA. In a consecutive series of patients undergoing primary TKA at a Veteran's Administration hospital, 40 patients (40 TKAs) who had local infiltration analgesia were compared to a historical group of 43 patients (43 TKAs) who had a long-acting femoral nerve block without local infiltration analgesia. Local infiltration analgesia consisted of intraoperative injection of 150 mL of 300 mg ropivacaine, 30 mg ketorolac, and 500 µg epinephrine using 50 mL into each of 3 areas: (1) posterior capsule, (2) medial and lateral capsule, and (3) anterior capsule and subcutaneous tissues. A 17-gauge intra-articular catheter was used to inject an additional 100 mg of ropivacaine on postoperative day 1. The control group had a single-shot femoral nerve block using 150 mg of ropivacaine with epinephrine. Mean length of stay for the local infiltration analgesia group compared to controls was 3.2±1.4 days vs 3.8±1.6 days, respectively (P=.03). No significant differences existed in average ROM (6 weeks), discharge hematocrit, transfusions, and temperature. Mean pain scores were lower in the local infiltration analgesia group on postoperative day 1 (P=.04), but not on postoperative day 2 or 3. Maximum visual analog scale scores (P<.01) were reduced in the local infiltration analgesia group. Our early experience with local infiltration analgesia demonstrated a significantly reduced length of stay due to decreased postoperative pain.

Acetabular component positioning using the transverse acetabular ligament: can you find it and does it help?

BACKGROUND: Several studies have reported that the transverse acetabular ligament (TAL) can be used to orient the acetabular component during total hip arthroplasty and that it can be identified in nearly all patients. QUESTIONS/PURPOSES: We attempted to determine how often the TAL could be identified during primary THA and its accuracy as a guide for acetabular component positioning. METHODS: In a prospective series of 63 patients (64 hips) undergoing primary THA, two surgeons attempted to identify the TAL and, if it was found, to use it for acetabular component orientation. Patients in whom the TAL was identified served as the study group and the ligament was used for cup orientation in those patients; the remaining patients in whom the ligament could not be identified served as a control group and had free-hand cup positioning. Anteversion was determined by radiographic measurement from true lateral views. RESULTS: The TAL was identified in only 30 hips (47%) and was more likely to be found in patients who did not have inferior acetabular osteophytes. Acetabular position was not improved using this ligament for reference. CONCLUSIONS: The TAL could not be routinely identified at surgery and when used for cup orientation it was no more accurate for cup positioning than free-hand technique.

Incidence of radiographic unicompartmental arthritis in patients undergoing knee arthroplasty.

Unicompartmental knee arthroplasty is increasing in popularity with the advent of less invasive procedures for knee arthritis. The percentage of patients undergoing knee arthroplasty who could be candidates for unicompartmental knee arthroplasty depends on the surgeon's evaluation of the radiographs, and this evaluation may depend on the surgeon's bias regarding partial knee arthroplasty. A retrospective radiographic and chart review was performed on a consecutive series of patients who had undergone tricompartmental knee arthroplasty to determine the percentage of those patients who could have been candidates for unicompartmental knee arthroplasty. Two hundred eighty-eight patients who underwent 308 tricompartmental knee arthroplasties over a 3-year period at a Veteran's Administration Hospital comprised the study group. Assessment of preoperative radiographs was done by 2 surgeons, 1 who favored unicompartmental knee arthroplasty and the other who preferred tricompartmental knee arthroplasty, to determine the percentage of these patients, from each surgeon's viewpoint, who had unicompartmental arthritis. Patients who had radiographic unicompartmental arthritis were then eliminated as candidates for unicompartmental knee arthroplasty, if, on chart review, they had a flexion contracture >10°, an arc of motion <100°, or inflammatory arthritis. The surgeon who was a proponent of unicompartmental knee arthroplasty found that 26% of these patients had acceptable radiologic and clinical indications for unicompartmental knee arthroplasty, whereas the surgeon who had a bias against the procedure felt that only 12% of these patients were unicompartmental knee arthroplasty candidates. A considerable percentage of Veteran's Administration patients undergoing arthroplasty for knee arthritis may be potential candidates for unicompartmental knee arthroplasty, despite the surgeon's bias for or against the procedure.

Minimal incision surgery as a risk factor for early failure of total hip arthroplasty.

BACKGROUND: Minimal incision total hip arthroplasty (MI THA) techniques were developed to decrease postoperative pain and recovery time. Although these techniques have increased in popularity, the long-term survivorship of these procedures is unknown. QUESTIONS/PURPOSES: We therefore investigated whether the time to revision in our referral practice was shorter for patients who underwent primary MI THA compared to primary traditional THA. METHODS: We retrospectively reviewed 46 revision THAs performed during a 3-year period. We excluded revisions performed for infection and rerevisions. Patients with incisions less than or equal to 10 cm were defined as having had MI THA. Fifteen of the 46 patients (33%) had undergone primary MI THA. At the time of primary index THA, the mean ages of the MI and non-MI patients were 65 years and 55 years, respectively. RESULTS: The mean time to revision was 1.4 years for the MI patients compared with 14.7 years for the non-MI patients. Twelve of the 15 patients having MI THA required revision within 2 years of primary THA compared to 4 of the 31 patients without MI surgery (OR = 26.5, 95% CI 4.4-160.0). There were no differences between the groups with regard to age, gender, or body mass index. The most common reasons for revision in the MI THA group were intraoperative fracture and failure of femoral component osseointegration. CONCLUSIONS: Our data suggest MI THA may be a risk factor for early revision surgery and the long-term survival therefore may be lower than that for non-MI surgery. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Hylamer vs conventional polyethylene in primary total hip arthroplasty: a long-term case-control study of wear rates and osteolysis.

The long-term results of Hylamer implants have not been reported previously. Clinical and radiographic results of a consecutive series of 43 patients (45 hips) who had primary total hip arthroplasty using Hylamer liners were compared with those of 37 patients (43 hips) who had conventional liners after 10-year follow-up. The linear wear rates for Hylamer and conventional polyethylene acetabular liners were 0.21 and 0.20 mm/y, respectively. The number of pelvic osteolytic lesions and their size detected on plain radiographs were significantly greater for Hylamer liners. Seven Hylamer hips were revised or are pending revision for osteolysis (16%) compared with 1 control hip. Close radiographic surveillance of patients who have Hylamer liners and evidence of osteolysis found on plain radiographs is warranted.

Primary total hip arthroplasty using an anterior approach and a fracture table: short-term results from a community hospital.

There are no data regarding the efficacy and safety of minimally invasive hip arthroplasty technique performed by community practice orthopedists. The early clinical and radiographic results of primary total hip arthroplasty using a minimally invasive anterior approach to the hip performed on a fracture table were studied. Two hundred thirty-one consecutive patients (247 hips) of 5 community practice surgeons were studied. The average surgical time (164 minutes) and estimated blood loss (858 mL) were more than double, and the major complication rate (9%) was 6 times that reported by an innovator of the procedure. However, no postoperative dislocations occurred. Adequate training is critical to reduce the risk of complications during the learning experience of minimally invasive hip arthroplasty procedures by community practice surgeons.

A comparison of the results of total hip and knee arthroplasty performed on a teaching service or a private practice service.

BACKGROUND: Active participation of residents and fellows in the performance of total hip and total knee arthroplasties may affect the outcomes of these procedures. We evaluated the early clinical results and complications associated with primary total hip and knee arthroplasties at a hospital that had both university teaching and private practice orthopaedic services. METHODS: We performed a retrospective study on a consecutive series of 347 patients who had undergone 230 total hip and 171 total knee procedures performed by one attending surgeon. One hundred and sixty-nine patients underwent an arthroplasty during which a resident or fellow on a teaching service assisted the attending surgeon; during these procedures, the resident or fellow performed part of the arthroplasty under the direct supervision of the attending surgeon. Subsequently, 178 patients underwent an arthroplasty performed by the same surgeon without resident or fellow participation. RESULTS: Significantly longer operative times were recorded for both total hip arthroplasty (average, seventy-three compared with sixty-one minutes; p < 0.0001) and total knee arthroplasty (average, eighty compared with seventy-three minutes; p = 0.0028) when the procedures were performed with the participation of residents or fellows. For total hip arthroplasty the complication rates were 8% for the teaching service and 10% for the private practice service, and for total knee arthroplasty they were 3% for each service. With the numbers studied, there were no differences in any clinical outcomes between the groups. CONCLUSIONS: Teaching and active participation from residents and fellows during total hip and total knee arthroplasty did not have a detrimental effect on the early clinical results, except for a longer surgical time.

In the absence of evidence--why bother? A literature review of minimally invasive total hip replacement surgery.

Two new total hip replacement (THR) procedures have been termed minimally invasive. It is claimed that these smaller incision techniques reduce soft-tissue trauma, decrease postoperative pain and blood loss, speed recovery, and reduce the length of the hospital stay compared with hip replacement using the standard incision technique. These new procedures use either one small 6- to 10-cm incision through a posterior, lateral, or anterior approach or two very small (a 2.5 cm posterior incision for placement of the femoral component and a 5-cm anterior incision for placement of the acetabular component) incisions to accomplish the same THR procedure that requires a standard length incision of 15 to 20 cm. Controversy exists on whether these small incision THRs are actually minimally invasive. It is debated whether a small skin incision that requires the application of high forces on the soft tissues for exposure of the joint but less muscle dissection will produce less overall trauma to the patient than a larger incision with wider muscle dissection but with lower retraction forces. If small incision THR techniques are less traumatic overall, then they should produce less pain, lower transfusion requirements, a shorter hospital stay, and a faster recovery for patients. The other important issues regarding small incision procedures are whether the decreased visualization provided by these techniques is adequate to prevent a higher complication rate from damage to the surrounding neurovascular structures and outcomes that are equivalent to those found for THR using the standard technique. A review of the literature to date provides no convincing evidence of any significant advantages of small incision THR compared with standard incision THR other than a shorter surgical scar. Comparison studies that prove both significant advantages and low complication rates for small incision THR are needed before these procedures can be recommended for general use.

Comparison of scars from total hip replacements done with a standard or a mini-incision.

UNLABELLED: Scar cosmesis is one of the proposed benefits of mini-incision total hip replacement as opposed to standard-incision procedures; however, there has been no scientific proof of this clinical outcome. The cosmetic appearances of healed incisions of 34 primary total hip replacement procedures done by one surgeon using either a mini-incision (20 procedures) or a standard-length incision (14 procedures) were compared at an average of 2 years postoperatively. Each scar's appearance was graded independently by two plastic surgeons using a standardized rating system. Patients answered a questionnaire regarding their subjective assessment of their scar. The blinded observers found that more mini-scars (six of 20) were rated poor than standard scars (one of 14) and that more standard-incision patients had scars that were rated good. More mini-incision patients (two of 20 versus zero of 14) had wound-healing problems. All the patients thought that their hip scar was acceptable in appearance, but 30 of 31 patients rated the relief of pain and total hip replacement longevity as higher priorities than scar cosmesis. The cosmesis of mini-incision total hip replacement scars may be inferior to standard-incision scars because of skin and soft tissue damage produced by high retractor pressures needed for exposure using a limited skin incision. LEVEL OF EVIDENCE: Therapeutic study, Level II-2 (prospective comparative study). See the Guidelines for Authors for a complete description of levels of evidence.

Comparison of primary total hip replacements performed with a standard incision or a mini-incision.

BACKGROUND: Primary total hip replacement performed through an incision that is

Mobile- vs. fixed-bearing total knee arthroplasty: a clinical and radiologic study.

A consecutive series of patients undergoing total knee arthroplasty (TKA) using either a mobile-bearing (MB) or a fixed-bearing (FB) implant were studied. Forty-four patients received 57 MB rotating platforms, and 40 patients received 45 FB posterior stabilized implants. At an average 41-month follow-up (range, 2-6 years), no significant differences were found between the groups with respect to Knee Society ratings or pain scores. Postoperative flexion was not different between the groups (116 degrees for MB and 118 degrees for FB). Three MB knees were revised for implant-related complications. There was no difference between these MB or FB knee implants clinically or radiographically at early follow-up. However, more patients with a MB knee required early revision for failure of rotating patellar or tibial polyethylene implants.