Second-generation cementless total hip arthroplasty. Eight to eleven-year results

Minimum 30-Year Results of Bilaterally Implanted Cemented and Cementless Total Hip Arthroplasty in Patients Younger Than 50 Years

BACKGROUND

The rate of failure of cemented and cementless total hip arthroplasty (THA) in younger patients is higher than that in elderly patients. The purpose of this study is to document the long-term clinical results of THA with the so-called third-generation cementing and the results of second-generation cementless THA in patients <50 years of age.

METHODS

This study included 106 patients who had had bilateral THA with a cemented stem in one hip and a cementless stem in the other. There were 78 men and 28 women. Their mean age was 47 years (range, 21-49). The average follow-up duration was 31 years (range, 30-32.5).

RESULTS

There were similar mean Harris Hip Scores (90 versus 91 points) between the groups at the final follow-up. Forty-six acetabular components (43%) in the cemented group and 48 acetabular components (45%) in the cementless group were revised. Five femoral components (5%) in the cemented group and 4 femoral components (4%) in the cementless group were revised. Survivorship of the acetabular component at 30.8 years was similar in both groups (57% in the cemented group versus 55% in the cementless group). Survivorship of the femoral component at 30.8 years was also similar in both groups (95% in the cemented group versus 96% in the cementless group).

CONCLUSION

Long-term fixation of the cemented or cementless femoral stem was outstanding. There was a high rate of the acetabular component revision due to conventional polyethylene wear and periacetabular osteolysis in both hybrid and fully cementless THA groups.

Selecting a Press-fit Stem for Total Hip Arthroplasty: The Rationale and Evolution of the Modern Femoral Prosthesis

Noncemented press-fit femoral stems predominate in total hip arthroplasty for all age groups with generally excellent long-term survivorship. The 2021 American Joint Replacement Registry reports that 96% of all elective primary total hip arthroplasties used noncemented femoral implant fixation. 1 Today, there are many styles of press-fit stems, each with supposed benefits, based on a range of design philosophies. Design aspects to consider when selecting a stem are numerous, including stem geometry, stem length, collared or collarless, material properties, and surface structure. Although most stem designs demonstrate excellent results, the differences in stem designs are intimately linked to additional factors such as ease of use/implantation, percentage of surface osseointegration, overall bone removal versus bone stock preservation, subsequent femoral stress shielding, and consideration of complexity of later revision. A surgeon with a broad understanding and appreciation of femoral stem designs should be prepared to select between the multitude of options to best serve individual patients.

Survival and complications of total hip arthroplasty using third-generation dual-mobility cups with non-cross-linked polyethylene liners in patients younger than 55years

BACKGROUND

In younger patients, total hip prostheses are subjected to wide motion ranges and wear-inducing forces. Dual-mobility cups (DMCs) are effective in decreasing the risk of dislocation. However, wear and osteolysis have been reported with first-generation DMCs. These complications have not been assessed in younger patients managed with third-generation DMCs associated with a lower risk of intra-prosthetic dislocation (IPD). We therefore designed a retrospective study of patients younger than 55years at THA with third-generation DMCs. Our objectives were to evaluate (1) the complication rate, and (2) the survival rate.

HYPOTHESIS

The rate of complications of THA with third-generation DMCs in patients younger than 55years of age is comparable to that in the general population of THA patients.

MATERIAL AND METHODS

This retrospective study included 79 consecutive patients (91 hips) who had total hip arthroplasty (THA) between 2007 and 2012. We included all patients younger than 55years who underwent primary THA with a third-generation DMC and a liner made of non-cross-linked polyethylene. The patients were evaluated clinically and radiologically.

RESULTS

Mean follow-up was 9.8years (range: 2-13years). At last follow-up, no patient had experienced prosthetic dislocation or IPD. Aseptic and septic cup loosening each occurred in 1 patient. In all, 7 (7.7%) patients required revision surgery with exchange of at least one component (cup loosening, n=2; neck fracture with a short stem fixed to the neck, n=1; peri-prosthetic femoral fracture, n=1; infection, n=1; and femoral-stem loosening, n=2). Peri-acetabular osteolysis developed in 2 (2.2%) hips. Cup survival to aseptic loosening was 98.9% (95% confidence interval, 97%-100%) and survival to revision for any reason except infection was 95.6% (95% confidence interval, 82%-100%).

DISCUSSION

In patients younger than 55years, third-generation DMCs were associated with absence of prosthetic dislocation, absence of IPD, and a low revision rate for cup loosening, in the medium term. These implants therefore constitute a viable treatment option in younger patients requiring THA.

LEVEL OF EVIDENCE

IV, retrospective study.

Long-Term Outcomes for Cementless Anatomic Femoral Components, Compared by Area of Porous Coating, in Patients Younger Than 50 Years Treated for Hip Dysplasia

BACKGROUND

We investigated whether the proximal circumferential porous coating of cementless stems would make implant survival of >20 years possible in young patients.

METHODS

Data for patients younger than 50 years with hip dysplasia who had an anatomic stem implanted with a proximal porous coating with hydroxyapatite/tricalcium phosphate were reviewed. Noncircumferential porous (non-C-type) stems were used in 17 hips (13 cases), and circumferential porous (C-type) stems were used in 87 hips (68 cases). Acetabular components with conventional polyethylene were used for all hips. The mean ages at surgery for patients with non-C-type stems and those with C-type stems were 43.3 and 44.7 years, respectively. Stems that had not loosened were retained at the time of acetabular revision. The average duration of follow-up for patients with non-C-type stems was 26.9 years and was 22.3 years for those with C-type stems.

RESULTS

Mean survival rates as determined by the Kaplan-Meier method were 74.9% at 20 years and 59.9% at 25 years for non-C-type stems and were 100% at 20 years and 94.0% at 25 years for C-type stems. The survivorship for C-type stems was significantly higher than that for non-C-type stems (P < .01). Focal osteolysis in the shoulder of 37 hips with C-type stems suppressed the spread of osteolysis to the distal femur.

CONCLUSION

Anatomic femoral stems with a circumferential porous coating provide excellent durability in patients with hip dysplasia who are 50 years of age or younger.

LEVEL OF EVIDENCE

Therapeutic Level IV.

Long-Term Outcomes of 496 Anatomical Cementless Modular Femoral Stems: Eleven to Twenty Years of Follow-Up

BACKGROUND

The aim of the study is to assess the long-term outcomes of this specific stem (anatomical cementless modular stem ESOP), to review the survivorship, complication rate, and radiographic and clinical outcomes.

METHODS

Descriptive and analytical retrospective longitudinal observational study of patients was operated on total hip arthroplasty between 1998 and 2007. Four hundred ninety-six prostheses corresponding to 447 patients were reviewed, mean age was 65.8 years (standard deviation [SD] ±11.6 years), and median follow-up time was 13.4 years (range 1-20). The most used cups were cementless (75.8%). The most frequent friction pairs were metal-polyethylene (53.1%) and ceramic-polyethylene (24.2%). Main variables analyzed were stem survival, subsidence, coronal orientation, osteolysis, reintervention, and Oxford Hip Score.

RESULTS

From 496 implants, there were 22 lost to follow-up (4.4%). Stem revision was performed in 51 patients: 26 periprosthetic joint infections (2-stage revision), 16 periprosthetic fractures, and 8 one-stage revisions (6 real aseptic loosening with negative culture after revision). The stem survivorship at more than 15 years for any reason was 89.2% and for aseptic loosening 97.97%. No specific complications were found due to modularity. The mean subsidence and orientation was 2.06 mm (SD ±5.11 mm) and 0.41° varus (SD ±2.20°) respectively. Subsidence >5 mm or varus >5° was associated with a higher revision rate. Osteolysis was found in 110 patients (zone I = 79, VII = 57), associated with zirconium-polyethylene, without relationship to the stem revision rate or Oxford Hip Score.

CONCLUSION

To our knowledge, this study represents the largest series of this stem, revealing an excellent survival rate and long-term clinical outcomes similar to the best results of classical cementless stems published in the literature.

Outcomes of total joint arthroplasty in patients with depression: A systematic review

BACKGROUND

Depression has been implicated as a poor predictor of outcomes after total joint arthroplasty (TJA) of the lower extremity in some studies. We aimed to determine whether depression as a comorbidity affects the TJA outcomes and whether pain reduction associated with successful TJA alters depressive symptoms.

METHODS

A search of PUBMED was performed using keywords "depression", "arthroplasty", "depressive disorder", and "outcomes." All English studies published over the last ten years were considered for inclusion. Quantitative and qualitative analysis was then performed on the data.

RESULTS

Thirty articles met inclusion criteria (16 retrospective, 14 prospective). Three showed that depressed patients were at higher risk for readmission. Two reported that depressed patients had higher likelihood of non-home discharge after TJA compared to non-depressed patients. Four noted that depressed patients incur higher hospitalization costs than non-depressed patients. Ten suggest depression is a predictor of poor patient-reported outcome measures, pain, and satisfaction after TJA. Five suggested the gains depressed patients experience in functional outcome scores after TJA are similar to gains experienced by patients without depression. Another eight suggested that TJA improves not only function and pain but also depressive symptoms in patients with depression.

CONCLUSION

The results of this review show that depression increases the risk of persistent pain, dissatisfaction, and complications after TJA. Additionally, depressed patients may incur higher costs than non-depressed patients undergoing TJA and may have worse preoperative and postoperative patient reported outcome measures (PROMs). However, the gains in function that depressed patients experience after TJA are equivalent to gains experienced by non-depressed patients and depressed patients may experience improvement in their depressive symptoms after TJA. Patient selection for TJA is critical and counseling regarding increased risk for complications is crucial in depressed patients undergoing TJA.

Satisfactory Outcomes in Patients Operated With Primary Total Hip Arthroplasty for Perthes-like Deformities: Results From a Surgical Technique Utilizing a Conical Stem, an Elevated Hip Center, and No Shortening Femoral Osteotomy

Background

Total hip arthroplasty (THA) performed on patients with Perthes-like deformities are technically challenging because of the patient's abnormal hip anatomy. Patients with Perthes-like deformities are at a higher risk of revision, aseptic loosening, nerve injury, and intraoperative fracture after THA, especially if shortening osteotomies are performed. This analysis sought to examine the clinical and radiographic outcomes of a patient cohort with Perthes-like deformities receiving THA with a conical stem, an elevated hip center, and no shortening femoral osteotomy.

Methods

Twenty-six patients (27 hips) received THA with MODULUS femoral stems, ceramic or metal femoral heads, and highly cross-linked polyethylene liners between April 2011 and March 2016. All patients were treated at a single center by 4 participating surgeons. Patients completed 2 questionnaires preoperatively and at the final follow-up visit (between 1 and 5 years postoperatively): Harris Hip Score and Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire. Differences in patient-reported outcome measures (PROM) scores were measured by paired t-tests. Preoperative and postoperative anteroposterior radiographs were analyzed to monitor patient outcomes.

Results

Significant clinical improvements were observed in all individual subcategories of the Harris Hip Score and of the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire; the largest magnitude improvements were observed in the subcategory of pain relief for both questionnaires. No complications, including intraoperative and postoperative femoral fractures, nerve palsy, dislocations, or deep venous thrombosis, were observed.

Conclusion

This study found that patients treated with an elevated hip center and low stem-positioning technique using a conical, modular implant system had good clinical outcomes and did not suffer complications at the mean follow-up from surgery of 2.8 years (range: 1-5 years).

Influence of outer geometry on primary stability for uncemented acetabular shells in developmental dysplasia of the hip

Excellent primary stability of uncemented acetabular shells is essential to obtain successful clinical outcomes. However, in the case of developmental dysplasia of the hip (DDH), aseptic loosening may be induced by instability due to a decrease of the contact area between the acetabular shell and host bone. The aim of this study was to assess the primary stability of two commercially-available acetabular shells, hemispherical and hemielliptical, in normal and DDH models. Synthetic bone was reamed using appropriate surgical reamers for each reaming condition (normal acetabular model). The normal acetabular model was also cut diagonally at 40° to create a dysplasia model. Stability of the acetabular components was evaluated by the lever-out test. In the normal acetabular model conditions, the maximum primary stabilities of hemispherical and hemielliptical shells were observed in the 1-mm under- and 1-mm over-reamed conditions, respectively, and the resulting stabilities were comparable. The lateral defect in the dysplasia model had an adverse effect on the primary stabilities of the two designs. The lever-out moment of the hemielliptical acetabular shell was 1.4 times greater than that of the hemispherical acetabular shell in the dysplasia model. The hemispherical shell is useful for the normal acetabular condition, and the hemielliptical shell for the severe dysplasia condition, in the context of primary stability.

Minimum 15-Year Results of a Dual-Offset Uncemented Femoral Stem in Total Hip Arthroplasty

BACKGROUND

The aim of the present study is to assess the long-term clinical and radiological outcomes of a proximal porous-coated, dual-offset, tapered titanium alloy uncemented stem at a minimum of 15 years of follow-up.

METHODS

We reviewed 210 total hip arthroplasties (in 193 patients) performed between 1996 and 1999 and followed prospectively in our database who received the Synergy stem. We report a Kaplan-Meier survival analysis as well as the Harris Hip Score, the Western Ontario and McMaster University Arthritis Index, and the Short Form Health Survey-12 scores. Radiographs were evaluated for evidence of subsidence, osteolysis, osteointegration, or loosening.

RESULTS

The average follow-up was 16 years (range, 15-17.7 years). Kaplan-Meier survival analysis with revision of stem for aseptic mechanical loosening (1 stem) as the end point revealed a cumulative survival rate of 99.5% at 16 years. The Harris Hip Score, the Western Ontario and McMaster University Arthritis Index, and the Short Form Health Survey-12 physical scores were all significantly improved (P < .001) from the preoperative period to latest follow-up. Minor osteolysis was observed proximally in 14 hips (6.6%) with no osteolysis distal to the porous coating.

CONCLUSION

To our knowledge, this study represents the largest series reporting the longest clinical follow-up of this third-generation, dual-offset, proximal ingrowth, tapered cementless stem. The Synergy stem design has achieved excellent clinical outcomes, predictable osteointegration, and outstanding survivorship of 99.5% at a minimum of 15 years follow-up, representing the standard for femoral stems at our institution.

Does proximal porous coating in short-stem humeral arthroplasty reduce stress shielding?

CONTEXT

Short-stem humeral designs in shoulder arthroplasty have been introduced recently. A retrospective cohort study was conducted to determine if newer proximal porous titanium coating in humeral short stems produced clinical and radiologic improvements.

METHOD

Short-stem humeral implants (Tornier Ascend, Wright Medical) were used in 46 anatomical total shoulder replacements from October 2012 to December 2015. Clinical and radiologic measures were analyzed at one- and two-year follow-up.

RESULTS

Nineteen shoulders received earlier grit blasted stems (Ascend Monolithic), and 27 shoulders received the later stems with proximal titanium porous coating (Ascend Flex). At two-year follow-up, radiographic changes and stress shielding were similar. Medial cortical thinning were more frequently observed in Monolithic (18 of 19) compared to Flex stems (19 of 27) on the PA films, though this was not statistically significant (P = 0.061). Clinical outcome scores improved regardless of the stem type used and independent of the radiologic adaptations on plain films. One participant with the Ascend Flex developed glenoid component failure and rotator cuff tear and was subsequently revised.

DISCUSSION

Clinical and radiological outcomes are similar in both short-stem designs. Proximal titanium porous coating may reduce medial calcar cortical thinning but it does not prevent it.

KEY MESSAGE

When compared to similarly designed uncoated grit-blasted stems, proximally porous coated humeral short stems produced similar clinical and radiological results. The proximal titanium porous coating may reduce medial cortical thinning.

Total ankle arthroplasty incorporating a total talar prosthesis

Aims

Total ankle arthroplasty (TAA) has become the most reliable surgical solution for patients with end-stage arthritis of the ankle. Aseptic loosening of the talar component is the most common complication. A custom-made artificial talus can be used as the talar component in a combined TAA for patients with poor bone stock of the talus. The purpose of this study was to investigate the functional and clinical outcomes of combined TAA.

Patients and Methods

Ten patients (two men, eight women; ten ankles) treated using a combined TAA between 2009 and 2013 were matched for age, gender, and length of follow-up with 12 patients (one man, 11 women; 12 ankles) who underwent a standard TAA. All had end-stage arthritis of the ankle. The combined TAA features a tibial component of the TNK ankle (Kyocera, Kyoto, Japan) and an alumina ceramic artificial talus (Kyocera), designed using individualized CT data. The mean age at the time of surgery in the combined TAA and standard TAA groups was 71 years (61 to 82) and 75 years (62 to 82), respectively. The mean follow-up was 58 months (43 to 81) and 64 months (48 to 88), respectively. The outcome was assessed using the Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot scale, the Ankle Osteoarthritis Scale (AOS), and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q).

Results

The mean preoperative JSSF score of the combined TAA and standard TAA groups was 44 (sd 11) and 49 (sd 10), respectively. The mean postoperative JSSF scores were 89 (sd 6.1) and 72 (sd 15), respectively. The mean postoperative JSSF score of the combined TAA group was significantly higher (p = 0.0034). The mean preoperative AOS scores for pain and function in the combined TAA and standard TAA groups were 5.8 (sd 3.3) and 5.5 (sd 3.1), and 8.6 (sd 1.3), and 7.1 (sd 2.9), respectively. The mean postoperative AOS scores of pain and function were 2.5 (sd 2.5) and 2.2 (sd 1.9), and 2.5 (sd 3.3) and 3.4 (sd 2.9), respectively. There were no significant differences between the two groups in terms of postoperative AOS scores. The mean postoperative SAFE-Q scores were: for pain, 76 (sd 23) and 70 (sd 23); for physical function, 66 (sd 25) and 55 (sd 27); for social function, 73 (sd 35) and 62 (sd 34); for shoe-related, 73 (sd 19) and 65 (sd 26); and for general health, 78 (sd 28) and 67 (sd 29), respectively. There were no significant differences between the two groups in terms of postoperative SAFE-Q scores.

Conclusion

Combined TAA resulted in better clinical results than standard TAA. Cite this article: Bone Joint J 2019;101-B:443–446.

Polyethylene Oxide and Silicon-Substituted Hydroxyapatite Composite: A Biomaterial for Hard Tissue Engineering in Orthopedic and Spine Surgery

BACKGROUND

Tissue engineering and biomaterials have made it possible to innovate bone treatments for orthopedic and spine problems. The aim of this study is to develop a novel polyethylene oxide (PEO)/silicon-substituted hydroxyapatite (Si-HA) composite to be used as a scaffold for hard tissue engineering in orthopedic and spine procedures.

MATERIALS AND METHODS

The composite was fabricated through the electrospinning technique. The applied voltage (5 kV) and PEO concentration (5%) were fixed. Processing parameters such as the flow rates (20 μl/min and 50 μl/min), distances from capillary tube to the collector (130 mm and 180 mm), spinning time (10 min and 20 min), and concentration of Si-HA (0.2% and 0.6%) were explored to find the optimum conditions to produce fine composite fibers.

RESULTS

Scanning electron microscope images showed that 5% PEO, 5% PEO/0.2% Si-HA, and 5% PEO/0.6% Si-HA fibers were successively produced. Flow rates and working distances showed significant influence on the morphology of the polymeric and composite fibers. A high flow rate (50 μl/min) and a larger working distance (180 mm) resulted in larger fibers. The comparison between the mean fiber diameter of 5% PEO/0.2% Si-HA and 5% PEO/0.6% Si-HA showed to be significantly different. As the Si-HA concentration increased, certain fibers were having particles of Si-HA that were not properly integrated into the polymer matrix.

CONCLUSIONS

Synthesis of a novel biomaterial for hard tissue scaffold through electrospinning was successful. In general, PEO/Si-HA fibers produced have the desired characteristics to mimic the extracellular matrix of bone.

Patients with a Dorr type C femoral bone require attention for using a Summit cementless stem: Results of total hip arthroplasty after a minimum follow-up period of 5 years after insertion of a Summit cementless stem

BACKGROUND

The Summit cementless stem has been used as a device to occupy the proximal medullary canal space in total hip arthroplasty (THA). The purpose of this study was to evaluate the mid-term clinical and radiographic results of the Summit stem and the differences in the results as a function of medullary cavity shape.

METHODS

This study analyzed the 90 consecutive patients who underwent THA by using the Summit cementless stem. The minimum clinical and radiographic follow-up period for the patients was 5 years (mean, 5.5 years; range, 5.0-7.1 years). The radiographic and Harris hip scores (HHS) were evaluated across the three Dorr type classifications of femoral bone.

RESULTS

The postoperative HHSs were significantly higher than the preoperative HHS scores (p < 0.05). No significant differences in preoperative and postoperative HHSs were found among the three Dorr types. Stress shielding was observed in 58 hips. Spot welds and cortical hypertrophy were observed in various zones in 53 and 11 hips, respectively. No significant difference in the number of occurrences of cortical hypertrophy was found among the three Dorr types. However, the number of occurrences of severe stress shielding in Dorr type C was higher than that in Dorr type B. The number of occurrences of spot welds in Dorr type C was lower than that in both Dorr types A and B.

CONCLUSIONS

Mid-term clinical results were good regardless of the medullary cavity shape. However, severe stress shielding in Dorr type C was more frequently than that in Dorr type B. Therefore, attention should be paid to the types of medullary cavity shapes for Summit stem use.

Initial stability of a highly porous titanium cup in an acetabular bone defect model

BACKGROUNDS

The purpose of this study was to quantify the initial stability of a highly porous titanium cup using an acetabular bone defect model.

METHODS

The maximum torque of a highly porous titanium cup, with a pore size of 640 μm and porosity of 60%, was measured using rotational and lever-out torque testing and compared to that of a titanium-sprayed cup. The bone models were prepared using a polyurethane foam block and had three levels of bone coverage: 100, 70, and 50%.

RESULTS

The highly porous titanium cup demonstrated significantly higher maximum torque than the titanium-sprayed cups in the three levels of bone defects. On rotational torque testing, it was found to be 1.5, 1.3, and 1.3 times stronger than the titanium-sprayed cups with 100, 70 and 50% bone coverage, respectively. Furthermore, it was found to be 2.2, 2.3, and 1.5 times stronger on lever-out testing than the titanium-sprayed cup. No breakage in the porous layers was noted during the testing.

CONCLUSION

This study provides additional evidence of the initial stability of highly porous titanium cup, even in the presence of acetabular bone defects.

Comparison of an Uncemented Tapered Stem Design in Cobalt-Chrome vs Titanium at 15-Year Follow-Up

BACKGROUND

Cobalt-chromium (Co-Cr) and titanium (Ti) have been the most popular materials employed for cementless implants. The purpose of this study was to compare clinical and radiological results of a single stem design with both alloys at long-term follow-up.

METHODS

Two hundred consecutive uncemented stems implanted in 171 patients (100 Co-Cr and 100 Ti implants) between 1999 and 2002 were studied. Mean age of the patients was 60.9 years (range, 20-84). Clinical results were evaluated using the Harris hip score. The presence of thigh pain was also analyzed. Stem fixation was graded according to Engh criteria. Radiolucent lines, osteolysis, and stem subsidence were also analyzed.

RESULTS

At 15-year follow-up, no stems had been revised. Both groups showed similar clinical results with mean Harris hip score of 93.4 (Co-Cr) vs 93.9 (Ti). There was no difference in the rate of thigh pain (11 vs 8.3, respectively, P = .507). Radiolucent lines were more frequent in the Co-Cr group (63.6% vs 35.6%, P < .001).

CONCLUSION

Ti stems showed better osteointegration than Co-Cr stems, with a significantly lower incidence of radiolucent lines. However, this did not affect the clinical results or the appearance of thigh pain.

Radiographic changes and clinical outcomes associated with an adjustable diaphyseal press-fit humeral stem in primary reverse shoulder arthroplasty

BACKGROUND

Press-fit humeral fixation in reverse shoulder arthroplasty (RSA) has become increasingly popular; however, radiographic analysis of these stems is limited. We aimed to evaluate the radiographic and clinical outcomes of an adjustable diaphyseal press-fit humeral stem in primary RSA.

METHODS

We conducted a retrospective review of 232 primary RSAs in 219 patients performed by a single surgeon using this system. Radiographic outcomes were evaluated in patients with at least 2 years of radiographic follow-up. Standardized postoperative digital radiographs were analyzed for loosening, osteolysis, and stress shielding. Clinical outcomes in patients who also had complete clinical data sets were evaluated at the most recent follow-up.

RESULTS

Radiographic evidence of loosening was identified in 1 RSA (0.4%) associated with deep infection. Aseptic loosening was not observed. No stems were identified as being at high risk for loosening. Internal stress shielding was observed proximal to the coated diaphyseal component in 226 shoulders (97.4%). This finding was often visible at 3 months (92.7%) and predictably progressed on subsequent radiographs. Progression beyond the 2-year period was rarely seen (4.4%). No external stress shielding or osteolysis was observed. Thirty-six complications occurred in 33 patients (15.1%). At an average follow-up of 36.6 months, significant improvements were identified in all measured clinical outcomes (P < .001).

CONCLUSION

Predictable fixation is achieved using an adjustable diaphyseal press-fit humeral system in primary RSA. Internal stress shielding is commonly observed but does not appear to compromise quality of fixation or clinical outcomes.

Porous Femoral Fixation in Total Hip Arthroplasty with Short Anatomical Stem: Radiographic Evaluation

Background

Hip prostheses with short anatomical stems were designed for metaphyseal fixation and to spare bone stock. We present a study of a short anatomical femoral stem used in all age groups of patients with Dorr A and B type of femora.

Methods

We reviewed radiographs of 85 hips in 74 patients who had a cementless total hip arthroplasty with a short anatomical 80 mm femoral stem designed to achieve pure metaphyseal fixation. A ream-only technique was used for femoral canal preparation in all patients. At each follow-up, radiological evaluation was performed for stem alignment, proximal metaphyseal fill, subsidence, status of biological fixation of the femoral stem, heterotrophic ossification, radiolucency, osteolysis, and limb length discrepancy of the stem. Acetabular components were evaluated for positioning, acetabular bone coverage, and radiolucent and osteolytic lesions.

Results

The final mean alignment of femoral stem was 2° valgus. The average intramedullary fill by the stem at the proximal level of the lesser trochanter was 93% in the coronal plane and 88% in the sagittal plane. No components were considered to be undersized. Thirteen hips (15.2%) presented radiolucent lines (10 hips < 1 mm in width and 3 hips [3.5%] 2 mm in width) and 100% of them were not progressive with respect to the last follow-up radiograph. All of the stems had excellent fixation by demonstrating bone ingrowth at the latest follow-up. At the last follow-up, heterotopic ossification was noted in 5 hips. The mean preoperative limb length discrepancy was 9.3 mm and the mean postoperative discrepancy was 3.8 mm. The mean acetabular component angle of the 85 components was 41.2° with a mean anteversion of 22.1°. At the last follow-up, there were no revisions of the femoral component. One patient, 25 months after the index operation, required an acetabular component revision because of recurrent hip dislocation. There were no radiological signs of loosening in any of the short-stem prostheses at the last examination.

Conclusions

The short, metaphyseal-fitting anatomic cementless femoral stem provided stable fixation without relying on diaphyseal fixation.

Proximal ingrowth coating decreases risk of loosening following uncemented shoulder arthroplasty using mini-stem humeral components and lesser tuberosity osteotomy

BACKGROUND

Mini-stem humeral component (MSHC) use during total shoulder arthroplasty (TSA) provides bone preservation and ease of revision. MSHCs rely solely on proximal metaphyseal fixation; some early reports have demonstrated an unacceptably high rate of early loosening. To our knowledge, no study analyzing the effect of proximal porous coating on MSHCs has been performed.

METHODS

We performed a retrospective review of consecutive patients who underwent anatomic TSA using coated or uncoated MSHCs with minimum 2-year follow-up. Postoperative radiographs were assessed for risk of or frank stem loosening, subsidence, and presence of radiolucencies. Range of motion, outcome scores (visual analog scale pain, American Shoulder and Elbow Surgeons, and Single Assessment Numeric Evaluation), and any complications were noted.

RESULTS

We analyzed 68 shoulders with a mean follow-up of 27.3 months (range, 24-50 months). Of these, 34 had proximal coating and 34 were uncoated. In the coated group, no stems loosened, 1 (2.9%) subsided, and 7 (20.6%) developed radiolucencies. In the uncoated group, 1 stem (2.9%) became aseptically loose (requiring revision after 26 months), 7 (20.6%) were judged at risk of loosening (2 because of subsidence), and 15 (44.1%) developed radiolucencies. There was also an increased risk of proximal medial humeral radiolucencies among uncoated MSHCs. There were no significant differences in final range of motion or outcome scores.

CONCLUSION

MSHC use is appropriate for TSA, achieving desired pain relief and functional improvement. Overall, component loosening appears uncommon at early follow-up; however, uncoated stems appear to be at greater risk of loosening and developing radiolucencies. Selecting an MSHC with proximal porous coating may decrease the risk of implant-related complications.

Total hip arthroplasty with step-cut subtrochanteric femoral shortening osteotomy in high riding hip dislocated patients with previous femoral osteotomy

BACKGROUND

To evaluate the long-term clinical and radiological outcomes of cementless total hip arthroplasty (THA) in high riding hip dislocated patients with previous proximal femoral osteotomy.

METHODS

Twenty-one consecutive patients with a mean age forty-two years were treated with cementless THA Step-cut subtrochanteric femoral osteotomy was performed in all twenty-eight hips. Metal on polyethylene (MoP) and ceramic on ceramic (CoC) bearings were used in two different consecutive time periods. The mean follow-up time was twelve years. Harris hip score, limb length discrepancy, complications, union status of the osteotomy, survivorship of constructs were the criteria for evaluation.

RESULTS

The mean Harris hip score improved from 39.5 to 88.7 points. The mean limb length discrepancy in unilateral cases decreased from 54.5 mm to 12.3 mm. The mean amount of femoral shortening was 37 mm. The mean union time was 3.5 months and there were no delayed union and non-union. There were three cup and two femoral revisions due to osteolysis in patients who had MoP. There was only one femoral revision in patients who had CoC. The Kaplan Meier survivorship with an end point of any revision of the stem and the acetabular component was 94% (95% CI, 75%-98%) and 92% (95% CI, 74%-99%) at ten years respectively.

CONCLUSIONS

Total hip arthroplasty with subtrochanteric step-cut femoral shortening is a successful technique to improve the hip functions and reconstruct limb length discrepancy in young patients with proximal femoral deformities.

The cementless fibre mesh coated anatomic femoral stem: 12 to 23 years clinical and radiological outcome study

INTRODUCTION

The aim of this study was to assess the long-term clinical and radiographic results, and possible reasons for failure of two versions of the cementless fibre-metal coated anatomical femoral component.

METHODS

99 patients (119 hips) were evaluated at an average of 16.7 years (range, 12 to 23 years) following primary THA. Developmental dysplasia of the hip (DDH) was the most common pathology (n = 37 hips). Structural femoral head autografts were used to increase cup coverage in 23 hips. Vertical and horizontal migration of acetabular and femoral components and osteolysis around the components were assessed using conventional radiolography. For clinical evaluation, the Harris Hip Score and Merle D'Aubigne scale were used preoperatively and at final follow up. Implant survival was calculated according to the Kaplan-Meier survivorship analysis and failure was defined as component's revision for any reason.

RESULTS

The cumulative survival rate of the anatomical femoral stem was 64.2% at 19.8 years, with a worst-case scenario of 41%. The cumulative survival rate of the total hip arthroplasty was 51% at 19.8 years, with a worse case scenario of 38%. The mean preoperative Harris Hip Score of 42 points improved to 88 postoperatively. The mean preoperative Merle D'Aubigne functional score of 3.5 improved to 5.2 points at the time of final follow-up. In 36 hips (41.6%) osteolysis was found in Gruen zone 1, proximal to the ingrowth surface.

CONCLUSIONS

The cementless fibre-metal coated anatomical femoral component showed favourable long-term clinical and radiological results. Proximal coating seems to protect bone implant interface from wear debris induced osteolysis during the second decade.

Radiographic evaluation of short-stem press-fit total shoulder arthroplasty: short-term follow-up

BACKGROUND

Humeral loosening is an uncommon etiology for revision shoulder arthroplasty. We aimed to evaluate the radiographic and clinical outcomes of a short-stem press-fit humeral component after primary total shoulder arthroplasty.

METHODS

We reviewed our patient database, from January 2008 to December 2011, for primary total shoulder arthroplasties performed with a short-stem press-fit humeral component. Radiographs and clinical outcomes were evaluated in the immediate postoperative period and at the most recent follow-up, with at least 24 months of data for all patients.

RESULTS

There were 73 shoulders that met our inclusion criteria, but 4 underwent revision before 2 years' follow-up. Only 1 of these 4 was revised for aseptic humeral loosening. Sixty-nine shoulders had at least 24 months of radiographic follow-up, and 62 had radiographic and clinical follow-up. Of the 69 shoulders, 5 underwent revision for humeral loosening: 1 for aseptic loosening and 4 for infection. Two other shoulders with humeral loosening were asymptomatic, and the patients refused revision surgery. The overall revision rate for humeral loosening was 8.2% (6 of 73 shoulders). Radiolucent zones of any size were seen in 71.0%, with 8.7% of these shoulders identified as having humeral stems at risk of future loosening. Significant improvements were made in most of the measured clinical outcomes.

CONCLUSIONS

A high percentage of radiolucency was seen around the short-stem press-fit humeral components evaluated in this study at short-term follow-up. The overall rates of loosening and revision for the humeral implant examined in this study are higher than those noted in other recent studies evaluating press-fit stems. The cause of radiolucency and humeral loosening for this implant is not fully understood.

Twenty-Five- to Twenty-Seven-Year Results of a Cemented vs a Cementless Stem in the Same Patients Younger Than 50 Years of Age

BACKGROUND

No study to our knowledge evaluated the long-term survivorship of the contemporary cemented vs cementless stems more than 25 years of follow-up in the same patients younger than 50 years of age.

PURPOSE OF STUDY

The purpose of the study is to determine (1) validated outcome scores, (2) prevalence of polyethylene wear and osteolysis, and (3) survivorship of the cemented vs cementless femoral components in the same young patients at minimum follow-up of 25 years.

METHODS

We report 171 patients (mean age, 47.7 years) at the time of the surgery who received simultaneous bilateral total hip arthroplasty with a cemented stem in one hip and a cementless stem in the other (26.1-year follow-up). A cementless acetabular component was used in all hips. There were 125 men and 46 women. The mean age at the time of the arthroplasty was 47.7 ± 10.7 years (range, 21-50 years).

RESULTS

The average Harris hip scores were similar between the groups of cemented stem (mean, 91 points) and cementless stem (93 points). Survival rate of the acetabular component (79% vs 78%) and that of the femoral component (96% vs 95%) at 26.1 years were similar between the 2 groups.

CONCLUSIONS

The long-term fixation of the acetabular metallic shell and cemented or cementless femoral stem was outstanding. Polyethylene wear and periacetabular osteolysis were contributing factors to reduce the long-term survival of the contemporary total hip arthroplasties with or without cement in young patients. New bearing surfaces such as ceramic on ceramic or ceramic on highly cross-linked polyethylene would improve wear of the bearing surfaces.

AVASCULAR NECROSIS OF THE FEMORAL HEAD IN HIV-INFECTED PATIENTS: PRELIMINARY RESULTS FROM SURGICAL TREATMENT FOR CERAMIC-CERAMIC JOINT REPLACEMENT

Objectives: To evaluate the initial functional results and early complication rate of ceramic-ceramic total hip replacements among patients living with HIV who presented osteonecrosis of the femoral head. Method: Twelve HIV–positive patients with a diagnosis of osteonecrosis of the incongruent femoral head were evaluated using clinical and laboratory criteria and the WOMAC functional scale before and after treatment with joint replacement. Results: We observed that 83.3% of the subjects were taking protease inhibitors, 75% had dyslipidemia and 66.6% had lipodystrophy syndrome. The improvement over the evolution of the WOMAC score was statistically significant at six and twelve months after the operation, in comparison with the preoperative score. We did not observe complications secondary to this procedure. Conclusion: Total hip arthroplasty with a ceramic-ceramic implant for treating avascular necrosis of the hip is an appropriate surgical option for this portion of the population. It provides a significant initial functional improvement and a low early complication rate.

Does Neuraxial Anesthesia Decrease Transfusion Rates Following Total Hip Arthroplasty?

Perioperative transfusions increase complications and cost following THA. Current series evaluating neuraxial anesthesia and blood loss following THA are small and utilize heterogeneous populations. Using the NSQIP database we compared transfusion rates following THA with neuraxial and general anesthesia. Between 2005 and 2012, 28,857 THAs (11,317 neuraxial anesthesia) were identified. Univariate analysis showed lower rates of transfusion, pneumonia, unplanned intubation, prolonged intubation, stroke, all complications, and medical complications in the neuraxial group. Operative time and length of stay were shorter with neuraxial anesthesia as well. After adjusting for patient comorbidities, a multivariate regression model showed fewer transfusions with neuraxial anesthesia. The multivariate regression model showed additional independent risk factors for transfusion including gender, operative time, elevated INR, and a history of hypertension, metastatic cancer, and renal failure.

Second-Generation Versus First-Generation Cementless Tapered Wedge Femoral Stems

Clinical outcomes of a new second-generation proximally coated, tapered wedge cementless stem were compared with those of its predecessor regarding (1) all-cause implant survivorship; (2) objective and subjective outcomes; (3) complications; and (4) radiographic features. Patients who underwent a primary total hip arthroplasty with the second-generation stem (68 hips) were compared with those who received the first-generation stem (136 hips) at a mean follow-up of 3.5 years. Although the first-generation stem was designed in the traditional manner, the second-generation stem was shortened to accommodate all surgical approaches and designed using a computed tomography scan-based database to enhance fit. The second-generation stem had survivorship, functional, and subjective outcomes similar to those of the first-generation stem.

Ten to fifteen-year clinical and radiographic follow-up with a third-generation cementless stem in a young patient population

PURPOSE

Outcome data beyond 11 years of follow-up is not available for the third-generation Zweymüller femoral stem in combination with a polyethylene bearing. We report ten to 15-year results with this total hip arthroplasty (THA) combination in a young population.

METHODS

A retrospective, observational, non-randomised, single-centre, clinical observational study was conducted in which 311 primary THAs were performed in 276 patients between 1996 and 2000 using a third-generation Zweymüller stem. The mean age of the patients at operation was 47.4 years (range 18-77 years).

RESULTS

Stem survival for any reason was 93.5% after ten years and 89.6% after 13 years, and the probability of aseptic stem loosening was 98.7% at both ten and 13 years. The occurrence of femoral radiolucent lines was low, at just 17.2%. Minor femoral osteolysis was identified in 30% of patients and was attributed to polyethylene liner wear. Clinical and patient satisfaction outcomes were in line with previous investigations, and the rate of adverse events was low.

CONCLUSIONS

The third-generation Zweymüller stem shows good radiographic and clinical results and good longevity, including in the younger osteoarthritic patient. The use of low-wear bearings may further reduce the rate of osteolysis and wear-related revision in young and active patients.

Machine oil inhibits the osseointegration of orthopaedic implants by impairing osteoblast attachment and spreading

The most important factor contributing to short-term and long-term success of cementless total joint arthroplasties is osseointegration. Osseointegration leads to a direct structural and functional connection between living bone and the surface of an implant. Surface contaminants may remain on orthopaedic implants after sterilization procedures and impair osseointegration. For example, specific lots of hip replacement Sulzer Inter-OP(TM) acetabular shells that were associated with impaired osseointegration and early failure rates were found to be contaminated with both bacterial debris and machine oil residues. However, the effect of machine oil on implant integration is unknown. Therefore, the goal of this study was to determine if machine oil inhibits the osseointegration of orthopaedic implants. To test this hypothesis in vivo we used our murine model of osseointegration where titanium alloy implants are implanted into a unicortical pilot hole in the mid-diaphysis of the femur. We found that machine oil inhibited bone-to-implant contact and biomechanical pullout measures. Machine oil on titanium alloy discs inhibited early stages of MC3T3-E1 osteogenesis in vitro such as attachment and spreading. Inhibition of osteoblast attachment and spreading occurred in both areas with and without detectable oil. Osteoblast growth was in turn inhibited on discs with machine oil due to both a decrease in proliferation and an increase in cell death. Later stages of osteogenic differentiation and mineralization on titanium alloy discs were also inhibited. Thus, machine oil can inhibit osseointegration through cell autonomous effects on osteoblast cells. These results support routine testing by manufacturers of machine oil residues on orthopaedic implants.

Comparison of Patient-Reported Outcome from Neck-Preserving, Short-Stem Arthroplasty and Resurfacing Arthroplasty in Younger Osteoarthritis Patients

Hip resurfacing has been considered a good treatment option for younger, active osteoarthritis patients. However, there are several identified issues concerning risk for neck fractures and issues related to current metal-on-metal implant designs. Neck-preserving short-stem implants have been discussed as a potential alternative, but it is yet unclear which method is better suited for younger adults. We compared hip disability and osteoarthritis outcome scores (HOOS) from a young group of patients (n = 52, age 48.9 ± 6.1 years) who had received hip resurfacing (HR) with a cohort of patients (n = 73, age 48.2 ± 6.6 years) who had received neck-preserving, short-stem implant total hip arthroplasty (THA). Additionally, durations for both types of surgery were compared. HOOS improved significantly preoperatively to last followup (>1 year) in both groups (p < 0.0001, η (2) = 0.69); there were no group effects or interactions. Surgery duration was significantly longer for resurfacing (104.4 min ± 17.8) than MiniHip surgery (62.5 min ± 14.8), U = 85.0, p < 0.0001, η (2) = 0.56. The neck-preserving short-stem approach may be preferable to resurfacing due to the less challenging surgery, similar outcome, and controversy regarding resurfacing implant designs.

Risk factors for early revision after total hip arthroplasty

OBJECTIVE

Revision total hip arthroplasty (THA) is associated with increased cost, morbidity, and technical challenge compared to primary THA. A better understanding of the risk factors for early revision is needed to inform strategies to optimize patient outcomes.

METHODS

A total of 207,256 patients who underwent primary THA between 1997-2005 in California and New York were identified from statewide databases. Unique patient identifiers were used to identify early revision THA (<10 years from index procedure). Patient characteristics (demographics, comorbidities, insurance type, and preoperative diagnosis), community characteristics (education level, poverty, and population density), and hospital characteristics (annual THA volume, bed size, and teaching status) were evaluated using multivariable regression to determine risk factors for early revision.

RESULTS

The probabilities of undergoing early aseptic revision and early septic revision were 4% and <1% at 5 years, respectively. Women were 29% less likely than men to undergo early septic revision (P < 0.001). Patients with Medicaid and Medicare were 91% and 24%, respectively, more likely to undergo early septic revision than privately insured patients (P = 0.01 and P < 0.001, respectively). Hospitals performing <200 THAs annually had a 34% increased risk of early aseptic revision compared to hospitals performing >400 THAs annually (P < 0.001).

CONCLUSION

A number of identifiable factors, including younger age, Medicaid, and low hospital volume, increase the risk of undergoing early revision THA. Patient-level characteristics distinctly affect the risk of revision within 10 years, particularly if due to infection. Our findings reinforce the need for continued investigation of the predictors of early failure following THA.

Hip resurfacing versus total hip arthroplasty: a systematic review comparing standardized outcomes

BACKGROUND

Metal-on-metal hip resurfacing was developed for younger, active patients as an alternative to THA, but it remains controversial. Study heterogeneity, inconsistent outcome definitions, and unstandardized outcome measures challenge our ability to compare arthroplasty outcomes studies.

QUESTIONS/PURPOSES

We asked how early revisions or reoperations (within 5 years of surgery) and overall revisions, adverse events, and postoperative component malalignment compare among studies of metal-on-metal hip resurfacing with THA among patients with hip osteoarthritis. Secondarily, we compared the revision frequency identified in the systematic review with revisions reported in four major joint replacement registries.

METHODS

We conducted a systematic review of English language studies published after 1996. Adverse events of interest included rates of early failure, time to revision, revision, reoperation, dislocation, infection/sepsis, femoral neck fracture, mortality, and postoperative component alignment. Revision rates were compared with those from four national joint replacement registries. Results were reported as adverse event rates per 1000 person-years stratified by device market status (in use and discontinued). Comparisons between event rates of metal-on-metal hip resurfacing and THA are made using a quasilikelihood generalized linear model. We identified 7421 abstracts, screened and reviewed 384 full-text articles, and included 236. The most common study designs were prospective cohort studies (46.6%; n = 110) and retrospective studies (36%; n = 85). Few randomized controlled trials were included (7.2%; n = 17).

RESULTS

The average time to revision was 3.0 years for metal-on-metal hip resurfacing (95% CI, 2.95-3.1) versus 7.8 for THA (95% CI, 7.2-8.3). For all devices, revisions and reoperations were more frequent with metal-on-metal hip resurfacing than THA based on point estimates and CIs: 10.7 (95% CI, 10.1-11.3) versus 7.1 (95% CI, 6.7-7.6; p = 0.068), and 7.9 (95% CI, 5.4-11.3) versus 1.8 (95% CI, 1.3-2.2; p = 0.084) per 1000 person-years, respectively. This difference was consistent with three of four national joint replacement registries, but overall national joint replacement registries revision rates were lower than those reported in the literature. Dislocations were more frequent with THA than metal-on-metal hip resurfacing: 4.4 (95% CI, 4.2-4.6) versus 0.9 (95% CI, 0.6-1.2; p = 0.008) per 1000 person-years, respectively. Adverse event rates change when discontinued devices were included.

CONCLUSIONS

Revisions and reoperations are more frequent and occur earlier with metal-on-metal hip resurfacing, except when discontinued devices are removed from the analyses. Results from the literature may be misleading without consistent definitions, standardized outcome metrics, and accounting for device market status. This is important when clinicians are assessing and communicating patient risk and when selecting which device is most appropriate for individual patients.

Primary Total Hip Arthroplasty Using Third Generation Ceramic-Ceramic Articulation: Results after a Minimum of Three-years of Follow-up

Purpose

This study assessed the short term clinicoradiological results of primary total hip arthroplasty using third generation ceramic-ceramic articulation Accolade TMZF femoral stems.

Materials and Methods

Two hundred and seventy two patients (294 hips) with primary total hip arthroplasty using third generation ceramic-ceramic articulation Accolade TMZF femoral stems who had been followed-up for a minimum of 3 years were included. Clinicoradiological results were analyzed and postoperative complications were observed.

Results

At final follow-up, mean Harris hip score was increased from 52 to 94 points. On radiogical evaluation, the average acetabular inclination was 42 degrees and the average acetabular anteversion was 15 degrees. Neither osteolysis nor loosening were observed around the acetabulum or proximal femur. Among 294 acetabular cups, 293 cups (99.66%) achieved stable fixation. Regarding the 294 femoral stems, 286 (97.28%) had bony fixation, 7 (2.38%) had fibrous fixation, and none were found to have unstable stem fixation. Proximal bone resorption was observed in 17 hips (5.78%; only Grade 1) and radiolucent lines were observed in 88 hips (29.93%), however, all were around the distal smooth portion of the stems. Postoperative complications included dislocation in 6 hips (2.04%), heterotopic ossification in 3 hips (1.02%), ceramic fractures in 4 hips (1.36%), superficial infection in 1 hip (0.34%), and squeaking in 8 hips (2.72%).

Conclusion

The short term clinicoradiological results of primary total hip arthroplasty using third generation ceramic-ceramic articulation and Accolade TMZF femoral stems together with Secur-Fit acetabular cups were satisfactory. However, problems such as ceramic fractures and squeaking after arthroplasty were observed. Additional studies are necessary in order to develop methods that may reduce or eliminate these complications.

High short-term loosening rates with the Wagner Standard Cup

The stability of prosthetic fixation is to a large extent dependent on component design. The purpose of this study is to analyze the short-term radiological results obtained with the Wagner Standard Cup in primary hip arthroplasty. An assessment was made of one hundred primary hip arthroplasties. The radiological evaluation revealed bone ingrowth in 37 of cases, fibrous integration in 49 and loosening in 14. In summary, osseointegration of the Wagner Standard Cup was unsuccessful in a high percentage of cases. This finding, which was unrelated to the type of stem or bearing surface used, bore a statistically significant relation (P<0.05) with an observed poor bone coverage of the acetabular component. Although insufficient bone coverage could arguably be attributable to a poor surgical technique, we would tend to agree with other authors that it is rather likely to result from a flawed implant design that impedes osseointegration.

The rationale for short uncemented stems in total hip arthroplasty

Uncemented femoral implants of various designs have proved to provide stable initial and long-term fixation in patients who undergo total hip arthroplasty. Challenges in primary total hip arthroplasty have led to the evolution of short stem designs. These challenges include proximal/metaphyseal and distal/diaphyseal mismatch; facilitation of less-invasive surgical exposures, especially the direct anterior approach; and bone preservation for potential revision surgery.

Cementless anatomic total hip femoral component with circumferential porous coating for hips with developmental dysplasia: a minimum ten-year follow-up period

Anatomic femoral components are optimized for primary osteoarthritis, and few long-term results for their use are available for developmental dysplasia of the hip (DDH). We reviewed 135 uncemented total hip arthroplasties in which an anatomic femoral component was used in 106 patients with DDH, excluding femurs with neck-shaft angles of >160° and femurs with anteversion of >50°. The mean age of patients at surgery was 49.4 years (range, 33-66 years), and the mean duration of follow-up was 13.5 years (range, 10-18 years). No osteoporotic femurs were included in our study group. Despite 18 acetabular revisions, no femoral component was removed for any reason. No femoral loosening was seen at the final follow-up examination. An anatomic femoral component with circumferential porous coating can produce good clinical and radiologic findings in young patients with good bone quality who have DDH without excessive femoral deformity.

Is the bone-bonding ability of a cementless total hip prosthesis enhanced by alkaline and heat treatments?

BACKGROUND

Cementless total hip arthroplasty (THA) implants using alkaline and heat treatments were developed to enhance bone bonding. Although bone-bonding ability of the alkali- and heat-treated titanium surface has been demonstrated in animal studies, it remains unknown whether it enhances or provides durable bone bonding in humans.

QUESTIONS/PURPOSES

We therefore (1) determined long-term survivorship, function, and radiographic signs of failure of fixation of alkali- and heat-treated THA implants; and (2) histologically examined their bone-bonding ability in two human retrievals.

METHODS

We retrospectively reviewed 58 patients who underwent 70 primary THAs, of whom 67 were available for minimum followup of 8 years (average, 10 years; range, 8-12 years). Survival rate was calculated. Hip function was evaluated using the Japan Orthopaedic Association (JOA) hip scores, and radiographic signs of implant failure were determined from anteroposterior radiographs. Two retrieved implants were investigated histologically.

RESULTS

Using revision for any reason as the end point, the overall survival rate was 98% (95% confidence interval, 96%-100%) at 10 years. The patients' average JOA hip scores improved from 47 points preoperatively to 91 points at the time of the last followup. No implant had radiographic signs of loosening. Histologically we observed bone in the pores 2 weeks after implantation in one specimen and apparently direct bonding between bone and the titanium surface in its deep pores 8 years after implantation.

CONCLUSIONS

Cementless THA implants with alkaline and heat treatments showed a high survival rate. Further study is required to determine whether the treatment enhances direct bone bonding.

Cementless femoral fixation

Cementless femoral stems are currently preferred for total hip replacement (THR) in the United States. Improvements in stem design, instrumentation and surgical technique have made this technology highly successful, reproducible, and applicable to the vast majority of patients requiring a THR. However, there are ongoing developments in some aspects of stem design that influence clinical results, the incidence of complications and their inherent adaptability in accommodating the needs of individual patients. Here we examine some of these design features.

Cite this article: Bone Joint J 2013;95-B, Supple A:53–6.

Results at a minimum of 10 years of follow-up for AMS and PerFix HA-coated cementless total hip arthroplasty: impact of cross-linked polyethylene on implant longevity

PURPOSE

The purpose of this study was to report results at a minimum of 10 years for hydroxyapatite (HA) coating on the titanium arc-sprayed cementless total hip arthroplasty (THA) and to evaluate the impact of cross-linked polyethylene (XLPE) on implant longevity.

METHODS

A total of 131 consecutive primary THAs in 123 patients using an AMS acetabular cup and a PerFix HA stem were retrospectively reviewed. Conventional PE was used for 62 hips (CPE group) and cross-linked PE for 69 hips (XLPE group), with mean follow-up periods of 13 and 11.5 years, respectively. These patients were reviewed using the Japanese Orthopaedic Association (JOA) Hip Score and evaluated in terms of PE wear, osteolysis, and implant survival.

RESULTS

The JOA score improved from 42.6 to 83.9 points at the final follow-up. The mean wear rate of 0.12 mm/year in the CPE group was significantly greater than that of XLPE at 0.007 mm/year. In the CPE group, ten (16.1 %) and two (3.2 %) hips, respectively, underwent PE exchange due to severe wear and acetabular revision due to loosening associated with osteolysis. Three patients had revision in the XLPE group: one cup for aseptic loosening, one PE for recurrent dislocation, and one stem for neck fracture. No evident osteolysis was seen in the XLPE group. Kaplan-Meier survivorship with any revision as the end point shows that the 12-year survival rate was 97.7 % for cups, 93.8 % for PE liners, and 99.2 % for stems. Multivariate analysis revealed that the use of XLPE significantly reduced the risk of revision, with the odds ratio (OR) of 4.3.

CONCLUSIONS

AMS and PerFix HA components in this series show excellent implant fixation; however, high rates of PE wear and subsequent osteolysis were limiting factors in long-term success. Low wear rates with XLPE suggest improved implant longevity.

Outcomes at least 10 years after cemented PF® (Zimmer) total hip arthroplasty: 83 cases

INTRODUCTION

Cementless total hip arthroplasty (TKA) is gaining ground over cemented TKA. The objective of this study was to assess survival rates of a cemented THA implant (PF(®), Zimmer), after at least 10 years and to assess changes in acetabular bone structure.

MATERIAL AND METHODS

Eighty-three ceramic-on-polyethylene THA prostheses were implanted between 1998 and 2001. Clinical outcomes were assessed using the Harris hip score and Postel Merle d'Aubigné score. For each hip, radiographs were examined for acetabular radiolucent lines, geodes, and granulomas; in addition, changes in bone structure and trabeculae were assessed comparatively to the other hip and classified from no change to severe osteolysis. Changes in trabeculae served to assess the loads applied to the bone. Polyethylene wear was assessed using the Livermore method.

RESULTS

A single patient was lost to follow-up. At last follow-up, 16 patients had died and six were contacted and had not required revision surgery; the remaining 52 patients (59 THAs) were re-evaluated and none had evidence of loosening. The Harris hip score at last evaluation was 91.6 compared to 60.5 preoperatively. No hips had evidence of acetabular osteolysis. For two hips, the radiographs showed complete acetabular radiolucent lines less than 2mm in width, with no mobilisation. Trabecular distribution was homogeneous with no stress shielding. Mean annual rate of wear was 0.08mm. No instances of femoral component loosening were recorded; granulomas involving no more than five Gruën zones were seen in three cases.

DISCUSSION

This study confirms the reliability of cemented THA, with a 12-year survival rate of 98.3%, in keeping with earlier data. Thus, our results establish that cemented ceramic-on-polyethylene prostheses remain valid options for THA.

LEVEL OF EVIDENCE

IV.

Early proximal migration of cups is associated with late revision in THA: a systematic review and meta-analysis of 26 RSA studies and 49 survivalstudies

BACKGROUND AND PURPOSE

The association between excessive early migration of acetabular cups and late aseptic revision has been scantily reported. We therefore performed 2 parallel systematic reviews and meta-analyses to determine the association between early migration of acetabular cups and late aseptic revision.

METHODS

One review covered early migration data from radiostereometric analysis (RSA) studies, while the other focused on revision rates for aseptic loosening from long-term survival studies. Thresholds for acceptable and unacceptable migration were classified according the Swedish Hip Arthroplasty Register and the Australian National Joint Replacement Registry: < 5% revision at 10 years.

RESULTS

Following an elaborate literature search, 26 studies (involving 700 cups) were included in the RSA review and 49 studies (involving 38,013 cups) were included in the survival review. For every mm increase in 2-year proximal migration, there was a 10% increase in revision rate, which remained after correction for age, sex, diagnosis, hospital type, continent, and study quality. Consequently, proximal migration of up to 0.2 mm was considered acceptable and proximal migration of 1.0 mm or more was considered unacceptable. Cups with proximal migration of between 0.2 and 1.0 mm were considered to be at risk of having revision rates higher than 5% at 10 years.

INTERPRETATION

There was a clinically relevant association between early migration of acetabular cups and late revision due to loosening. The proposed migration thresholds can be implemented in a phased evidence-based introduction, since they allow early detection of high-risk cups while exposing a small number of patients.

Ten- to 15-year clinical and radiographic results for a compression molded monoblock elliptical acetabular component

The aim of this study was to report the long-term results from a previously published midterm follow-up of a titanium monoblock, elliptical acetabular component. A total of 258 primary total hip arthroplasties (212 patients) with a monoblock, acetabular component were followed up for a mean period of 11.1 years (10-15). Average yearly wear rate was 0.08 mm/y (0.0009-0.32). Acetabular radiolucencies were present in 6 hips (2.4%); all were nonprogressive and present in acetabular zone I. Acetabular osteolysis was present in 5 patients (5 hips, 1.9%); all cups were stable. Four acetabular components were revised, 3 because of recurrent instability. No acetabular components were revised for polyethylene wear or dissociation, acetabular osteolysis, loosening, or deep infection. This monoblock design demonstrates excellent long-term survival and low rate of osteolysis.

Circular external fixator-assisted ankle arthrodesis following failed total ankle arthroplasty

BACKGROUND

Failed total ankle arthroplasty (TAA) often results in significant bone loss and requires salvage arthrodesis. This study quantified the bone loss following failed TAA and reports the outcome of seven arthrodesis reconstructions using the Ilizarov method.

METHODS

A retrospective review of ankle fusions was performed for failed TAA to collect the mode of implant failure, presenting limb length discrepancy (LLD), total bone defect, postarthrodesis LLD, and treatment type (shoe lift versus distraction osteogenesis) and amount (shoe lift or lengthening).

RESULTS

Four mechanical failures and three infections were found. Four of seven cases had prior revision TAAs. Four of seven patients were treated with tibiotalar arthrodesis; three of the seven patients required talar resection and tibiocalcaneal arthrodesis. The mean presenting LLD was 2.2 (range, 1.2 to 3.5) cm. The mean time in frame was 197 (range, 146 to 229) days. With a mean postexplantation total bone defect of 5.1 (range, 3.7 to 8.5) cm, four of seven patients elected tibial lengthening following fusion [mean lengthening 4.6 (range, 2.5 to 8.0) cm; external fixation index (EFI) 42.6 (range, 16.5 to 55.6) days/cm)]. Three of seven patients were treated with a shoe lift [mean lift height 2.9 (range 2.5 to 3.2) cm]. There was no failure of fixation, refracture, or infection. All patients had a stable plantigrade foot and walked with minimal limp. Association for the Study and Application of the Method of Ilizarov (ASAMI) functional scores were six good and one fair. ASAMI bone scores were four excellent and three good.

CONCLUSIONS

Ankle arthrodesis following failed TAA results in large LLDs secondary to bone loss during implant failure and subsequent explantation. External fixation can produce an excellent fusion rate in complex, possibly infected, failed TAAs. Limb length equalization (by either distraction osteogenesis or shoe lift) provides a means of obtaining good functional outcomes following failed TAA.

Minimally invasive versus conventional joint arthroplasty

With an aging population, as well as a heightened interest in physical activity, the demand for surgical treatment of osteoarthritis of the knee, hip, and shoulder has continued to expand. This demand traditionally has been met with total joint replacements as the definitive treatment. However, with the development of newer, minimally invasive techniques, patients are being offered a greater variety of options for pain relief and improvement in function. These surgical options, varying widely from arthroscopic treatment to partial joint replacements, have been met with mixed results as they have been applied to the treatment of osteoarthritis. Although they are limited in their application and target population, minimally invasive procedures may greatly enhance the outcome of the patient, as well as prevent or delay the need for future total joint arthroplasty. The purpose of this article is to review minimally invasive surgical options for the treatment of osteoarthritis of the hip, knee, and shoulder. We also examine their appropriate application, limitations, clinical outcomes, and associated complications. A brief review of total joint arthroplasty for the aforementioned joints has been included to provide a comparison of the associated clinical outcomes and surgical complications.

Comparison of ten-year survivorship of hip prostheses with use of conventional polyethylene, metal-on-metal, or ceramic-on-ceramic bearings

BACKGROUND

To improve the long-term performance of hip prostheses, alternative bearings with metal-on-metal (MoM) and ceramic-on-ceramic (CoC) couples have been introduced. Although currently the results from the use of these bearings are in the midterm stage, there have been few comparative studies of these different bearings.

METHODS

From 2000 to 2002, 487 total hip replacements were performed with use of a BICON-PLUS acetabular cup and an SL-PLUS femoral stem (Plus Orthopedics, Rotkreuz, Switzerland, now Smith & Nephew Orthopaedics). The patients were divided into three groups according to the type of bearing that was used: an MoM group (sixty-nine prostheses), a metal-on-polyethylene (MoP) group (200 prostheses), and a CoC group (218 prostheses). Patient demographic data and data with regard to revision operations were evaluated from the hospital computer database. The mean follow-up period was 8.5 years (range, 6.9 to 10.5 years). Patient activity was assessed with use of the University of California at Los Angeles activity scale.

RESULTS

The mean patient age was sixty years at the time of the index arthroplasty in the MoM and CoC groups, and seventy-one years in the MoP group. Based on a scale of ten, the mean postoperative activity level was six in the CoC group, five in the MoM group, and four in the MoP group. Survival at ten years with regard to revision for any reason was 0.984, 0.956, and 0.879 for the MoP, CoC, and MoM groups, respectively. When revision for any reason was considered as the end point, survival of the MoM bearings was significantly worse than that of the MoP bearings (p = 0.005). Survival at ten years with regard to revision for aseptic loosening was 0.995, 0.990, and 0.894 for the MoP, CoC, and MoM groups, respectively. When revision for aseptic loosening was considered as the end point, survival of the MoM group was significantly worse than that of either the MoP group (p = 0.001) or the CoC group (p = 0.003).

CONCLUSIONS

When comparing two groups of patients of similar mean age and mean activity level undergoing total hip arthroplasty with the use of alternative bearings, CoC bearings had better survival than did MoM bearings at the ten-year follow-up; the difference was significant when revision for aseptic loosening was defined as a failure. However, neither the CoC nor the MoM alternative bearings provided improved midterm results when compared with the results of the conventional MoP bearings. For older, less active patients, traditional metal-on-polyethylene bearings are the appropriate choice.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Minimally invasive surgical approaches and traditional total hip arthroplasty: a meta-analysis of radiological and complications outcomes

Background

Minimally invasive total hip arthroplasty (MITHA) remains considerably controversial. Limited visibility and prosthesis malposition increase the risk of post-surgical complications compared to those of the traditional method.

Methods

A meta-analysis was undertaken of all published databases up to May 2011. The studies were divided into four subgroups according to the surgical approach taken. The radiological outcomes and complications of minimally invasive surgery were compared to traditional total hip arthroplasty (TTHA) using risk ratio, mean difference, and standardized mean difference statistics.

Results

In five studies involving the posterolateral approach, no significant differences were found between the MITHA groups and the TTHA groups in the acetabular cup abduction angle (p = 0.41), acetabular anteversion (p = 0.96), and femoral prosthesis position (p = 0.83). However, the femoral offset was significantly increased (WMD = 3.00; 95% CI, 0.40–5.60; p = 0.02). Additionally, there were no significant differences among the complications in both the groups (dislocations, nerve injury, infection, deep vein thrombosis, proximal femoral fracture) and revision rate (p>0.05). In three studies involving the posterior approach, there were no significant differences in radiological outcomes or all other complications between MITHA or TTHA groups (p>0.05). Three studies involved anterolateral approach, while 2 studies used the lateral approach. However, the information from imaging and complications was not adequate for statistical analysis.

Conclusions

Posterior MITHA seems to be a safe surgical procedure, without the increased risk of post-operative complication rates and component malposition rates. The posterolateral approach THA may lead to increased femoral offset. The current data are not enough to reach a positive conclusion that lateral and anterolateral approaches will result in increased risks of adverse effects and complications at the prosthesis site.

Fixation of an anatomically designed cementless stem in total hip arthroplasty

Purpose. The Anatomic Fiber Metal plus stem (Zimmer) is one of the anatomically designed cementless stems to achieve stable fixation by metaphyseal fit. We studied outcomes of cementless total hip arthroplasty using this stem and possible effects of metaphyseal fit on outcomes. Methods. The cementless total hip arthroplasty using this stem was performed for 155 hips. One hundred and thirty-seven hips of 122 patients were followed for 5 to 16 (mean, 9.7) years and entered into the study. The metaphyseal fit was defined as good or poor in an anteroposterior radiograph after surgery. We studied the fixation of the stem and bone reaction on an anteroposterior radiograph at the final followup. Results. Twelve hips had revision, six acetabular components and six acetabular liners. No stem was revised. The biological fixation of the stem was bone ingrown fixation for 136 hips and unstable for one. The metaphyseal fit was good for 83 hips and poor for 54 hips. There were no differences for stem fixation and bone reaction between the two groups. Conclusions. The fixation of the stem was stable at a mean followup of 9.7 years independently from metaphyseal fit.

Survivorship of second-generation metal-on-metal primary total hip replacement

BACKGROUND

Second generation metal-on-metal total hip replacements (THR) were introduced in the late 1980s and various studies reported conflicting data on their outcome.

METHODS

Implant survival of 1,270 second-generation 28 mm metal-on-metal primary THR in 1,121 patients followed prospectively at a mean of 6.8 years postoperatively was evaluated retrospectively. The probability of survival at 10 years was estimated using the method of Kaplan and Meier, and relative risk factors including age, gender, BMI, type of implant fixation and component size were calculated using the Cox proportional-hazards model.

RESULTS

Sixty-three (5%) THRs were revised, these being 28 hips for aseptic loosening and 35 for reasons other than aseptic loosening. The probability of survival at 10 years, with revision for any reason as the endpoint, was 0.90 (95% confidence interval (CI) 0.86-0.94) for the THR as a whole, 0.91 (95% CI 0.87-0.95) for the cup, and 0.96 (95% CI 0.94-0.98) for the stem. No demographic factors or covariates were found to significantly affect the implant survivorship.

DISCUSSION

As there was no superior probability of survival, and there have been concerns on putative local and systemic toxicity of metal debris, the use of second-generation metal-on-metal articulations for primary THR remains moot.

[Cementless total hip arthroplasty: a review]

The purpose of total hip replacement (THR) is the restoration of a painless functioning hip joint with the main focus on the biomechanical properties. Advances in surgical techniques and biomaterial properties currently allow predictable surgical results in most patients. Despite the overwhelming success of this surgical procedure, the debate continues surrounding the optimal choice of implants and fixation. Femoral and acetabular implants with varying geometries and fixation methods are currently available. Problems inherent with acrylic bone cement, however, have encouraged surgeons to use alternative surfaces to allow biologic fixation. Optimal primary and secondary fixation of cementless hip stems is a precondition for long-term stability. Important criteria to achieve primary stability are good rotational and axial stability by press-fit fixation. The objective of the cementless secondary fixation is the biological integration of the implant by bony ingrowth. Nevertheless, current investigations show excellent results of cementless fixation even in older patients with reduced osseous quality. The main advantages of cementless fixation include biological integration, reduced duration of surgery, no tissue damage by cement polymerization and reduction of intraoperative embolisms. In comparison to cemented THR both, cementless sockets and stems provide good long-term results.

Second-generation modular acetabular components provide fixation at 10 to 16 years

BACKGROUND

First-generation modular titanium fiber-metal-coated acetabular components had high rates of wear, pelvic osteolysis, and liner dissociation. Second-generation components were designed to reduce the incidence of these problems but it is unclear whether the changes achieved these goals.

QUESTIONS/PURPOSES

We asked the following questions: (1) Is the risk of revision surgery for loosening, wear, or liner dissociation low with the second-generation acetabular component? (2) Is the rate of pelvic osteolysis low? (3) Can the liner be exchanged without bone cement?

METHODS

We retrospectively reviewed prospectively collected data from 99 patients (118 hips) undergoing THAs with one second-generation modular titanium acetabular component with routine screw fixation and conventional polyethylene. The minimum followup was 10 years (mean, 12 years; range, 10-16 years). We obtained Harris hip scores and examined radiographs for loosening and osteolysis.

RESULTS

At last followup, all acetabular components were well fixed and no titanium shell had been revised or removed. No liner had dissociation. At most recent followup, the mean Harris hip score was 89. We observed pelvic osteolysis in eight hips (7%). There were three reoperations for dislocation (head-liner exchange only) and three loose femoral components revised. Two liners (at 11 and 14 years) were exchanged for wear-pelvic osteolysis.

CONCLUSIONS

This second-generation modular titanium fiber-metal-coated acetabular component with screw fixation had no loosening, no liner dissociation, and a low rate of pelvic osteolysis at 10 to 16 years. Liner exchange is practical without use of cement. We continue to use this component with highly crosslinked polyethylene liners.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.