Amar S. Ranawat

The Squeaking Hip: A Phenomenon of Ceramic-on-Ceramic Total Hip Arthroplasty

BACKGROUND Early reports on modern ceramic-on-ceramic total hip replacements have demonstrated excellent clinical and radiographic results with few cases of catastrophic failure, which, in the case of earlier designs, often had been caused by implant fracture. Several reports, however, have noted the presence of audible squeaking. The purpose of the present study was to determine the incidence of squeaking in association with the use of this bearing couple. METHODS During the period from March 2003 to May 2005, three surgeons performed 159 total hip arthroplasties in 143 patients with use of a ceramic-on-ceramic bearing. One hundred and forty-nine hips (131 patients) were available for review after at least one year of follow-up. These patients were followed prospectively with use of the modified Hospital for Special Surgery hip score and a patient-administered questionnaire. Additionally, a control group of sixty hips (forty-eight patients) with a metal-on-polyethylene bearing was matched to the ceramic group on the basis of age, sex, and body mass index to compare the incidence of squeaking and other noises. Radiographic evaluations were performed according to previously established criteria. RESULTS Fourteen (10.7%) of 131 patients described an audible squeak during normal activities. However, squeaking was reproducible clinically in only four patients, and only one patient complained of squeaking before being presented with the questionnaire. The average Hospital for Special Surgery score improved from 19.8 preoperatively to 38.4 at the time of the latest follow-up, indicating excellent clinical results. Ninety-five percent of the patients had a satisfaction score of > or =8 of 10. Three hips dislocated. One of those three hips squeaked and was revised because of recurrent dislocations. One patient was considering revision because of squeaking. In the matched metal-on-polyethylene cohort, there were no cases of squeaking. CONCLUSIONS The squeaking hip is a phenomenon that is unique to total hip replacements with hard-on-hard bearings. The incidence of squeaking in association with ceramic-on-ceramic bearings may be higher than previously reported as <1% of the patients in the present study reported this finding before being queried. The causes and implications of squeaking are yet to be determined. The use of hard-on-hard bearings offers many advantages in terms of wear reduction, especially for young and active patients. Nonetheless, patients considering ceramic-on-ceramic bearings should be counseled with regard to this phenomenon.

Total knee arthroplasty for severe valgus deformity.

BACKGROUND In 1985, the senior author (C.S.R.) developed a new soft-tissue release technique to balance valgus knees to avoid unacceptably high rates of late-onset instability and the need for primary constrained implants. This report describes the soft-tissue release technique and its long-term results when performed in primary total knee arthroplasty in patients with a severe valgus knee deformity. METHODS Four hundred and ninety consecutive total knee arthroplasties were performed by one surgeon between January 1988 and December 1992. In this group, seventy-one patients (eighty-five knees) had a valgus deformity of 10 degrees . Thirty-two patients (thirty-six knees) died, and four patients (seven knees) were lost to follow-up, leaving thirty-five patients (forty-two knees) followed for a minimum of five years. These twenty-seven women and eight men had a mean age of sixty-seven years at the time of the index operation. The technique included an inside-out soft-tissue release of the posterolateral aspect of the capsule with pie-crusting of the iliotibial band and resection of the proximal part of the tibia and distal part of the femur to provide a balanced, rectangular space. Cemented, posterior stabilized implants were used in all knees. Clinical and radiographic evaluations were performed at one, five, and ten years postoperatively. RESULTS The mean modified Knee Society clinical score improved from 30 points preoperatively to 93 points postoperatively, and the mean functional score improved from 34 to 81 points. The mean range of motion was 110 degrees both preoperatively and postoperatively. The mean coronal alignment was corrected from 15 degrees of valgus preoperatively to 5 degrees of valgus postoperatively. Three patients underwent revision surgery because of delayed infection, premature polyethylene wear, and patellar loosening in one patient each. There were no cases of delayed instability. CONCLUSIONS The inside-out release technique to correct a fixed valgus deformity in patients undergoing primary total knee arthroplasty is reproducible and provides excellent long-term results.

Total knee arthroplasty for severe valgus deformity: Five to fourteen-year follow-up

BACKGROUND In 1985, the senior author (C.S.R.) developed a new soft-tissue release technique to balance valgus knees to avoid unacceptably high rates of late-onset instability and the need for primary constrained implants. This report describes the soft-tissue release technique and its long-term results when performed in primary total knee arthroplasty in patients with a severe valgus knee deformity. METHODS Four hundred and ninety consecutive total knee arthroplasties were performed by one surgeon between January 1988 and December 1992. In this group, seventy-one patients (eighty-five knees) had a valgus deformity of > or =10 degrees . Thirty-two patients (thirty-six knees) died, and four patients (seven knees) were lost to follow-up, leaving thirty-five patients (forty-two knees) followed for a minimum of five years. These twenty-seven women and eight men had a mean age of sixty-seven years at the time of the index operation. The technique included an inside-out soft-tissue release of the posterolateral aspect of the capsule with pie-crusting of the iliotibial band and resection of the proximal part of the tibia and distal part of the femur to provide a balanced, rectangular space. Cemented, posterior stabilized implants were used in all knees. Clinical and radiographic evaluations were performed at one, five, and ten years postoperatively. RESULTS The mean modified Knee Society clinical score improved from 30 points preoperatively to 93 points postoperatively, and the mean functional score improved from 34 to 81 points. The mean range of motion was 110 degrees both preoperatively and postoperatively. The mean coronal alignment was corrected from 15 degrees of valgus preoperatively to 5 degrees of valgus postoperatively. Three patients underwent revision surgery because of delayed infection, premature polyethylene wear, and patellar loosening in one patient each. There were no cases of delayed instability. CONCLUSIONS The inside-out release technique to correct a fixed valgus deformity in patients undergoing primary total knee arthroplasty is reproducible and provides excellent long-term results. LEVEL OF EVIDENCE Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

Hydroxyapatite-coated femoral stems. A matched-pair analysis of coated and uncoated implants.

Fifty-two pairs of patients who had had a total hip arthroplasty with a porous-coated femoral implant were studied in a retrospective, matched-pair analysis. Half of the patients had received a femoral component coated with hydroxyapatite and the other half (the controls), an identical component but without hydroxyapatite. The patients were matched for age, sex, weight, diagnosis, Charnley class, operative approach, and duration of follow-up. Identical uncoated hemispherical acetabular implants were used in both groups. At the time of follow-up, at a mean of 2.2 years (range, two to 3.4 years) after the operation, the mean Charnley scores for pain, function, and motion were 5.6, 5.5, and 5.6 points, respectively, in the group that had received a hydroxyapatite-coated femoral component and 5.6, 5.6, and 5.6 points, respectively, in the group that had received a non-coated component; none of these differences were significant (p = 0.86, 0.89, and 0.80, respectively). There were no revisions in either group. Radiographs indicated stable fixation in both groups and no differences in the radiographic parameters of loosening between the two groups. Within the relatively short time-frame of this study, there appeared to be no clinical or radiographic advantage to the use of hydroxyapatite in primary total hip arthroplasties. However, these results should be considered as preliminary. Longer follow-up may reveal unrecognized advantages or disadvantages.

Pain management after total knee arthroplasty using a multimodal approach.

Improvements in pain management techniques over the past decade have had a significant impact on the outcomes of total knee arthroplasty. Of these techniques, multimodal approaches have shown potential. The purpose of this study was to compare the results of periarticular injection (PAI) to a combination of patient-controlled epidural analgesia and femoral nerve block (PCEA/FNB). Ninety patients undergoing primary unilateral total knee arthroplasty between June 2010 and March 2011 were randomized into 2 groups. The first group received the PCEA/FNB protocol, whereas the second group received the PAI. Mean patient age was 66.1 ± 8.7 years. All patients were operated on using a similar standard medial parapatellar approach, and all received preemptive analgesia and postoperative pain protocols. All patients were interviewed twice daily for the first 3 days postoperatively, once on day 7, and once in month 6. The 2 groups had similar readiness for discharge (PCEA/FNB group, 3.3 ± 1.2 days; PAI group, 3.2 ± 1.9 days). The results indicated no statistical difference between the 2 groups in 3 of 4 categories (rest in the morning, rest in the evening, and ambulation in the morning). Pain on ambulation was the only category that was statistically lower in the PCEA/FNB group than in the PAI group.Although the study demonstrates similar results between the 2 groups, PAI can play a major role in postoperative pain control in institutions that may not have appropriately trained individuals, equipment, and resources for PCEA/FNB. It also reduces many of the side effects and complications associated with regional anesthesia.

Revision total hip arthroplasty for ceramic head fracture: a long-term follow-up.

The results of revision total hip arthroplasty (THA) for ceramic head fracture have generally been disappointing, largely due to third body wear after incomplete synovectomy. We have followed 8 patients who sustained ceramic head fractures and were subsequently revised to a metal-on-polyethylene articulation. There were no revisions for osteolysis or aseptic loosening at a mean follow-up of 10.5 years. The yearly wear rates of each of 5 of these THAs after revision were compared with 6 matched metal-on-polyethylene THAs; there were no significant differences in wear rates. Greater than 10-year survivorship with a metal-on-polyethylene bearing couple is possible after revision THA for a ceramic head fracture if a complete and thorough synovectomy can be performed. Our technique of synovectomy will be described.

Minimally invasive total joint arthroplasty: where are we going?

The purpose of total joint arthroplasty of the hip and knee is to safely and effectively relieve pain, restore motion, and improve function. In less than three months, the vast majority of patients can return to the activities of daily living and can participate in certain sports. As a result, total joint arthroplasty has become one of the most successful and widely acclaimed procedures of the modern era. Recently, minimally invasive surgery, which involves a smaller incision (defined as <10 cm) or multiple smaller incisions, has been introduced to both hip and knee replacement surgery1-3. The premise is to reduce the trauma of surgery while maintaining the perceived high levels of safety, efficacy, and durability of the procedure. If it is done successfully, patients can expect a shorter hospital stay, quicker recovery, faster rehabilitation, improved function, and better cosmetic appearance, which should …

Pregabalin and pain after total knee arthroplasty: a double-blind, randomized, placebo-controlled, multidose trial

BACKGROUND Pregabalin may reduce postoperative pain and opioid use. Higher doses may be more effective, but may cause sedation and confusion. This prospective, randomized, blinded, placebo-controlled study tested the hypothesis that pregabalin reduces pain at 2 weeks after total knee arthroplasty, but increases drowsiness and confusion. METHODS Patients (30 per group) received capsules containing pregabalin (0, 50, 100, or 150 mg); two capsules before surgery, one capsule twice a day until postoperative day (POD) 14, one on POD15, and one on POD16. Multimodal analgesia included femoral nerve block, epidural analgesia, oxycodone-paracetamol, and meloxicam. The primary outcome was pain with flexion (POD14). RESULTS Pregabalin did not reduce pain at rest, with ambulation, or with flexion at 2 weeks (P=0.69, 0.23, and 0.90, respectively). Pregabalin increased POD1 drowsiness (34.5, 37.9, 55.2, and 58.6% in the 0, 50, 100, and 150 mg arms, respectively; P=0.030), but did not increase confusion (0, 3.5, 0, and 3.5%, respectively; P=0.75). Pregabalin had no effect on acute or chronic pain, opioid consumption, or analgesic side-effects. Pregabalin reduced POD14 patient satisfaction [1-10 scale, median (first quartile, third quartile): 9 (8, 10), 8 (7, 10), 8 (5, 9), and 8 (6, 9.3), respectively; P=0.023). Protocol compliance was 63% by POD14 (50.0, 70.0, 76.7, and 56.7% compliance, respectively), with no effect of dose on compliance. Per-protocol analysis of compliant patients showed no effect of pregabalin on pain scores. CONCLUSIONS Pregabalin had no beneficial effects, but increased sedation and decreased patient satisfaction. This study does not support routine perioperative pregabalin for total knee arthroplasty patients. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov: http://www.clinicaltrials.gov/ct2/show/study/NCT01333956.

Management of Failed Trochanteric Fracture Fixation With Cementless Modular Hip Arthroplasty Using a Distally Fixing Stem

Failure of internal fixation of intertrochanteric fractures is associated with delayed union or malunion resulting in persistent pain and diminished function. We evaluated 15 elderly patients treated with a tapered, fluted, modular, distally fixing cementless stem. At an average follow-up of 2.86 years, mean Harris hip score improved from 35.90 preoperatively to 83.01 (P < .01). Fourteen stems had stable bony on growth, and one stem was loose. Distal fixation with a tapered, fluted, modular cementless stem allows stable fixation with good functional outcome in a reproducible fashion in this challenging cohort of patients.

Haptically guided robotic technology in total hip arthroplasty: A cadaveric investigation

The longevity of total hip arthroplasty (THA) continues to improve with advancements in design and bearing materials. However, the incidence of dislocation and impingement-related failures continue to rise, with the inability of the surgeon to achieve optimal component orientation cited as a cause. Computer-assistance has been shown to increase the accuracy of component orientation and robotic-assistance has been developed to translate this advantage into precise surgical execution. We sought to validate a haptically-guided robotic arm system in performing THA with the aim of comparing the accuracy of robotic-assisted acetabular cup placement to manual placement. We implanted 12 acetabular components in 6 cadaveric pelvises comparing robotic-assistance on one side with manual implantation on the other. We measured planned and actual center of rotation (COR), cup position, leg-length equalization and offset for each THA using computed tomography and the robotic platform. The root-mean-square (RMS) error for the robotic-assisted system was within 3° for cup placement and within 1mm for leg-length equalization and offset when compared to computed tomography. The robotic-assisted system was significantly more accurate than manual implantation in reproducing the COR and cup orientation, as determined by a preoperative plan. The RMS error for manual implantation compared to robotic-assistance was 5 times higher for cup inclination and 3.4 times higher for cup anteversion (p < 0.01). Robotic-assistance is more accurate than manual implantation in achieving optimal cup orientation. It has the ability to eliminate human error from THA and should be considered in light of THA failures due to component malposition.