Clinical experience with a proximally porous-coated second-generation cementless total hip prosthesis: minimum 5-year follow-up

Long-term survival and complication rate of cementless prosthetic stems in primary total hip arthroplasty categorized by types according to Mont classification: a regional registry-based study on 53,626 implants

INTRODUCTION

The purpose of this retrospective registry-based study is to assess survival and causes of failure of cementless stem implants used in total hip arthroplasty (THAs), to ascertain if there are differences when these are categorized according to the six types described by Mont.

METHODS

Data collected from the regional registry regarding all primary THAs performed from 2000 to 2019 were analyzed. Femoral prosthetic stems were divided into the six types of Mont classification. For each stem type, number of implants, survival and causes of failure were evaluated and compared.

RESULTS

The most frequently implanted stem type was the 3c type (53.4%). Type 1 had the lowest stem failure rate (1.6%), and type 6 showed the highest (3.9%). Periprosthetic fracture was the most frequent complication in type 6, accounting for 34.5% of failures. Aseptic loosening was the main complication in type 2 stems, accounting for 36.4% of failures. Pairwise comparisons showed significant higher survival of type 1 compared to type 3c (p = 0.000026) and type 6 (p = 0.000076), and between type 3a compared to type 3c (p = 0.03) and type 6 (p = 0.026).

CONCLUSION

Significant variations in implant survival rates were found among the six Mont-types of cementless stems. These findings emphasize the paramount importance of stem design and fixation area in determining long-term survival, providing a guidance for orthopedic surgeons in the selection of the most appropriate stem for primary THA, contributing to our understanding of cementless stem performance, presenting invaluable insights to further improve patient outcomes in THA surgery.

Retrospective Analysis of Ultrasound-Guided Serial-Injection Triple Nerve Block Efficacy in Cementless Bipolar Hemiarthroplasty for Femoral Neck Fracture

BACKGROUND

Femoral neck fractures are effectively treated with bipolar hemiarthroplasty (BHA) surgery, yet postoperative pain management remains a challenge. This study explores the efficacy of multimodal pain management in minimizing opioid use and enhancing recovery.

METHODS

A retrospective analysis of 87 patients who underwent BHA between September 2016 and September 2020 was conducted. Patients were analyzed in two groups: Group I (n = 42), receiving serial-injection nerve blocks (SINBs) before and after surgery, and Group II (n = 41), with no SINB. Notably, all nerve blocks for Group I were performed after November 2017, following the implementation of this technique in our protocol. Pain and analgesic medication usage were assessed over 72 h post-surgery, along with hospitalization duration and perioperative complications.

RESULTS

Group I patients exhibited significantly lower pain scores at 6, 12, 24, and 48 h post-surgery, alongside reduced incidences of postoperative nausea and vomiting (PONV) and delirium compared with Group II (p < 0.05).

CONCLUSIONS

Utilizing sequential lower limb nerve blocks under ultrasound guidance in BHA surgeries effectively reduces early postoperative pain and associated adverse effects. This approach demonstrates potential benefits in pain management, leading to diminished narcotic usage and lower risks of PONV and delirium.

Effectiveness of ultrasound-guided dual nerve block in the below-knee amputation

PURPOSE

Below knee amputation (BKA) is a common surgical procedure for diabetic foot ulcers and necrotizing lower limb fasciitis patients. However, it is a painful procedure and inadequate postoperative analgesia impedes rehabilitation and prolongs hospitalization. An ideal pain management regimen should provide superior analgesia while minimizing opioid consumption and improving rehabilitation.

METHODS

We retrospectively reviewed medical charts of 218 patients who underwent BKA for diabetic foot ulcer or necrotizing lower limb fasciitis at a single center between January 2017 and September 2020. Two groups were analyzed: patients who received dual nerve block (DNB) before surgery (Group I; n = 104), and patients who did not (Group II; n = 93). By the exclusion criteria, 21 patients were excluded. The femoral and sciatic nerves were each blocked separately under ultrasound guidance. This procedure was performed immediately before the operation.

RESULTS

Group I patients' subjective pain scores were significantly lower than that of Group II at 6, 12, and 24 h after BKA (P < 0.05). Group I's morphine milligram equivalent (MME) was significantly lower than those of Group II at 72 h after BKA (P < 0.05). Moreover, the rate of postoperative nausea and vomiting (PONV) and delirium was significantly lower in Group I patients than that in Group II patients.

CONCLUSION

Ultrasound-guided lower extremity nerve block surgery is excellent for early postoperative pain control, could be used as an accurate and effective pain control method, and can reduce the side effects of opioid consumption after BKA.

Short stems have lower load at failure than double-wedged stems in a cadaveric cementless fracture model

Objectives

Periprosthetic femoral fractures (PFFs) have a higher incidence with cementless stems. The highest incidence among various cementless stem types was observed with double-wedged stems. Short stems have been introduced as a bone-preserving alternative with a higher incidence of PFF in some studies. The purpose of this study was a direct load-to-failure comparison of a double-wedged cementless stem and a short cementless stem in a cadaveric fracture model.

Methods

Eight hips from four human cadaveric specimens (age mean 76 years (60 to 89)) and eight fourth-generation composite femurs were used. None of the cadaveric specimens had compromised quality (mean T value 0.4 (-1.0 to 5.7)). Each specimen from a pair randomly received either a double-wedged stem or a short stem. A materials testing machine was used for lateral load-to-failure test of up to a maximal load of 5000 N.

Results

Mean load at failure of the double-wedged stem was 2540 N (1845 to 2995) and 1867 N (1135 to 2345) for the short stem (p < 0.001). All specimens showed the same fracture pattern, consistent with a Vancouver B2 fracture. The double-wedged stem was able to sustain a higher load than its short-stemmed counterpart in all cases. Failure force was not correlated to the bone mineral density (p = 0.718).

Conclusion

Short stems have a significantly lower primary load at failure compared with double-wedged stems in both cadaveric and composite specimens. Surgeons should consider this biomechanical property when deciding on the use of short femoral stem.

Cite this article: A. Klasan, M. Bäumlein, P. Dworschak, C. Bliemel, T. Neri, M. D. Schofer, T. J. Heyse. Short stems have lower load at failure than double-wedged stems in a cadaveric cementless fracture model. Bone Joint Res 2019;8:489–494. DOI: 10.1302/2046-3758.810.BJR-2019-0051.R1.

Cementless hip implants: an expanding choice

INTRODUCTION

Total hip replacement is a successful procedure with long survival records compared to other joint arthroplasties. Cemented implants have been available for many years, however the complications associated with loosening and, ultimately, failure over time has led to the development of cementless stems and implants.The ideal prosthesis should recreate a biomechanically normal hip joint, allow pain-free function and last the patient's life span without requiring revision. Optimal results with uncemented femoral stems rely on obtaining initial stability, osseointegration, biological fixation, and uniform stress transfer to the proximal bone.There are a multitude of factors that can affect the integration, stability and fixation of these stems into bone, and understanding these factors is the key to choosing the appropriate implant for a specific femur.

METHODS

This article aims to discuss cementless prostheses based on evidence-based practice. Geometry, roughness, stem coating, technique and bone quality are among the factors discussed. This was achieved through a review of the current literature.

CONCLUSIONS

Uncemented femoral stems have shown good, long-term survivorship and functional outcome, with promising results in younger patients.Limitations in the current literature make it difficult to assess and compare different designs to determine optimal indications for each type.Biological fixation, in which the prosthesis is directly fixed to the bone, is the preferred fixation method.Future studies of cementless implants should consistently address patient age, activity level, bone type, and deformities so that more definitive conclusions can be drawn about when to use each design.

Excellent survivorship with the use of proximally coated tapered cementless stems for total hip arthroplasty in octogenarians

The use of total hip arthroplasty (THA) continues to grow partially because of the increasing life expectancy of the American population. Whether to use cemented or cementless femoral fixation options in older patients is often debated. The purpose of the present study was to compare the clinical and radiographic outcomes after cementless THA in patients ≥80 years to younger patients. Clinical and radiographic data were gathered on 33 patients (35 hips) all 80 years or older who had undergone proximally coated cementless total hip arthroplasties. Outcomes were compared with a matching group for age, body mass index, and diagnosis, who had undergone the same procedure by the same surgeon at a similar time. Harris hip scores were evaluated pre- and postoperatively, and radiographs were reviewed for evaluation of fixation and stability. At a mean follow-up of 4 years, 97% of the hips (34 of 35) remained unrevised and the mean Harris hip score had improved by 39 points to 83 points (range, 26-100 points). On radiographic evaluation, 91% were found to have full bony ingrowth, with 1 hip having osteolysis of the proximal femur. Mortality was 23% at 86 months. Except for mortality, the outcomes and complication rates were similar to the younger group except that the matching group had higher final postoperative Harris hip scores. Proximally coated tapered cementless THA is a safe and efficacious method for providing good clinical outcomes with low revision rates in patients 80 years of age or older.

Prevention of Orthopaedic Implant Infection in Patients Undergoing Dental Procedures

The Prevention of Orthopaedic Implant Infection in Patients Undergoing Dental Procedures evidence-based clinical practice guideline was codeveloped by the American Academy of Orthopaedic Surgeons (AAOS) and the American Dental Association. This guideline replaces the previous AAOS Information Statement, "Antibiotic Prophylaxis in Bacteremia in Patients With Joint Replacement," published in 2009. Based on the best current evidence and a systematic review of published studies, three recommendations have been created to guide clinical practice in the prevention of orthopaedic implant infections in patients undergoing dental procedures. The first recommendation is graded as Limited; this recommendation proposes that the practitioner consider changing the long-standing practice of routinely prescribing prophylactic antibiotic for patients with orthopaedic implants who undergo dental procedures. The second, graded as Inconclusive, addresses the use of oral topical antimicrobials in the prevention of periprosthetic joint infections. The third recommendation, a Consensus statement, addresses the maintenance of good oral hygiene.

Numerical simulation of the insertion process of an uncemented hip prosthesis in order to evaluate the influence of residual stress and contact distribution on the stem initial stability

The long-term success of a cementless total hip arthroplasty depends on the implant geometry and interface bonding characteristics (fit, coating and ingrowth) and on stem stiffness. This study evaluates the influence of stem geometry and fitting conditions on the evolution and distribution of the bone-stem contact, stress and strain during and after the hip stem insertion, by means of dynamic finite element techniques. Next, the influence of the mechanical state (bone-stem contact, stress and strain) resulted from the insertion process on the stem initial resistance to subsidence is investigated. In addition, a study on the influence of bone-stem interface conditions (friction) on the insertion process and on the initial stem stability under physiological loading is performed. The results indicate that for a stem with tapered shape the contact in the proximal part of the stem was improved, but contact in the calcar region was achieved only when extra press-fit conditions were considered. Changes in stem geometry towards a more tapered shape and extra press fit and variation in the bone-stem interface conditions (contact amount and high friction) led to a raise in the total insertion force. A direct positive relationship was found between the stem resistance to subsidence and stem geometry (tapering and press fit), bone-stem interface conditions (bone-stem contact and friction interface) and the mechanical status at the end of the insertion (residual stress and strain). Therefore, further studies on evaluating the initial performance of different stem types should consider the parameters describing the bone-stem interface conditions and the mechanical state resulted from the insertion process.

Total hip arthroplasty with an HPF stem: the radiological findings around the cementless anatomical-shape stem for developmental dysplasia of the hip

BACKGROUND

We developed the HPF stem to suit the Japanese femoral bone marrow canal in developmental dysplasia of the hip. This anatomical-shape cementless stem improves canal occupation by the lateral and anterior flares. We report the clinical performance of the stem and details of the change in the X-rays, especially of the femoral side.

MATERIALS AND METHODS

We investigated 53 joints of total hip arthroplasty using the stem in 48 cases. The follow-up period was 8 years on average. We checked the Harris hip score (HHS) for clinical assessment. Existence of postoperative thigh pain was also investigated. For radiological assessment, the direction of stem insertion and initial fixation mode immediately after surgery were estimated. At the latest follow-up, we estimated the radiological findings of bone atrophy, spot welds, radiolucent zone, osteolysis, and sinking of the stem over 2 mm. Biological fixation was classified into four types: bone ingrowth, ingrowth suspected, suboptimum, and unstable fixation.

RESULTS

HHS was improved from 44 points before surgery to 92 points at the final follow-up. Light thigh pain appeared temporarily in three joints after surgery. Press-fit was achieved in femurs including total fit in 12 femurs, proximal fit in 4, middle fit in 25, and distal fit in 2. First degree stress shielding was seen in 25 femurs and second degree in 28. Forty-eight joints showed bone-ingrowth fixation, and five joints were ingrowth-suspected.

DISCUSSION

The clinical performance was excellent. Total or proximal fit was seen in only 30%. In these joints, cortical hypertrophy at the middle part of the stem and slight proximal bone atrophy appeared frequently, suggesting the stress transmission to the stem middle or distal portion, and there is a limit to the stress shielding evasion by the anatomical-shape stem.

Cementless femoral fixation in total hip arthroplasty

A number of cementless femoral stems are associated with excellent long-term survivorship. Cementless designs differ from one another in terms of geometry and the means of obtaining initial fixation. Strict classification of stem designs is important in order to compare results among series. Loosening and thigh pain are less prevalent with modern stem designs. Stress-shielding is present in most cases, even with newer stem designs.

Partial weightbearing is not necessary after cementless total hip arthroplasty: a two-year prospective randomized study on 100 patients

The purpose of this study was to evaluate the effects of partial and full weightbearing after cementless total hip arthroplasty over a two year follow-up period. Fifty-nine women and 41 men (average age 61 years) received an uncemented Spotorno stem and were randomised into a full and a partial weightbearing group. No significant difference was found between the groups with regard to the Merle d' Aubigne hip score, VAS pain level, shaft migration or radiographic signs of bony ingrowth. All femoral components seemed radiologically well-fixed and showed bone ingrowth at 24 months. Provided that solid initial fixation is obtained full weightbearing immediately after cementless total hip arthroplasty using a hydroxyapatite-coated Spotorno-type femoral shaft component can be recommended.

Mid-term results of 155 patients treated with a collum femoris preserving (CFP) short stem prosthesis

Short stem prostheses that preserve the femoral neck are becoming more and more popular. The CFP (collum femoris preserving) has been introduced especially for the treatment of younger patients. However, information about remodelling, complications and learning curve are thus far rare. We present a retrospective study of 155 patients (average age 59.3 ± 9.9 years) who underwent total hip replacement with the CFP prosthesis. Follow-up was obtained 74.3 ± 9.4 months postoperatively. The Harris hip score revealed excellent and good results in 96%. One stem had to be exchanged due to aseptic loosening revealing a survival rate of 99% and 100% for stem and cup, respectively. Radiological analysis showed typical patterns of remodelling with appearance of cortical thickening predominantly in the distal part of the prosthesis. Implant related revision rate was <1%, with further complication rate independent of the surgeon's individual experience. With regard to outcome, survivorship and complication rate, the medium-term results of the CFP prosthesis are promising.

Second-generation uncemented stems: excellent 5-13-year results

INTRODUCTION

The purpose of this study was to prospectively evaluate the 5-13-year results of a cementless total hip arthroplasty with a special focus on the survivorship,occurrence of osteolysis, incidence of intraoperative femoral fractures, thigh pain, and cortical hypertrophy of the femoral stem. The femoral component used in this study was titanium fluted, slotted, symmetrical component that was prepared with intraoperative machining. The proximal third of the stem had hydroxyl-apatite coating and horizontal steps.

METHODS

The clinical and radiographical results of a consecutive series of 157 total hip arthroplasties (124 patients)with this stem were investigated. Minimum follow-up was 5 years. The average age of the patients at the time of surgery was 47 years. Three patients died and ten patients were lost to follow-up, leaving 142 hips for evaluation. The clinical result was evaluated on the basis of the Merled’Aubigné score, complications and thigh pain. A detailed radiographic analysis was performed at each follow-up visit. Kaplan–Meier survivorship analysis was performed to evaluate stem, cup, and bearing survivorship.

RESULTS

The mean follow-up was 8.5 years (range 5-13 years). The average Merle d’Aubigné score improved from 10.5 points preoperatively to 17.4 points postoperatively.The cumulative 10-year survival rate was 99% for the femoral component, 99% for the acetabular component,and 69% for the bearing. Thigh pain was identified in three patients (2%). There was no distal femoral osteolysis.Seventy-nine percent of all the hips had endosteal spot welds around the coated, proximal one-third of the prosthesis.51% had radio dense lines around the distal tip of the prosthesis,and 3% had cortical hypertrophy. One undersized stem and one cup were revised for aseptic loosening, and 25 bearings were exchanged.

CONCLUSIONS

Uncemented, machined, fluted titanium canal-filling femoral components achieve reliable fixation in this young patient population. They have a decreased incidence of activity-related thigh pain, lower rate of intraoperative femur fractures and cortical hypertrophy with comparable bone-ingrowth in comparison to other second generation uncemented femoral components described in literature. Bearing wear and the need for bearing exchange was the only limitation of these constructs.

Outcome of uncemented primary femoral stems for treatment of femoral head osteonecrosis

Cementless total hip replacement has been advocated for patients with osteonecrosis of the femoral head. This study examined the outcome of the femoral stem of four generations of an uncemented, proximally porous-coated, chrome-cobalt total hip prosthesis. There were 158 cases in 141 osteonecrosis patients (74 men, 67 women) who had a mean age of 46 years (range, 17-83 years). The mean follow-up was 103 months (range, 20-235 months). The femoral components of 144 cases were not revised and had a mean Harris hip score of 84 (+/-15) at final follow-up. Of the 14 revisions (8.9%), the primary reasons for revision were loosening or significant osteolysis. There were one infection and one chronic dislocation. Proximally porous-coated, anatomic, press-fit stems provide excellent long-term results in patients with osteonecrosis of the femoral head.

A proximally coated beaded stem minimum 5-year follow-up

This study reports the minimum 5-year clinical and radiographic outcome of a proximally beaded stem. A consecutive series of 159 primary uncemented total hip arthroplasties in 153 patients were evaluated clinically and radiographically by prospectively determined criteria. Radiographic results showed 97% of the femoral stems are bone ingrown and stable by Engh criteria. There have been 5 femoral revisions (2 for subsidence, 2 for loosening, and 1 broken trunion). At minimum 5-year follow-up, this femoral stem has demonstrated reliable clinical function, bone ingrowth, and proximal bone preservation.

Revision total hip replacement using cemented collarless double-taper femoral components

We investigated 219 revisions of total hip replacement (THR) in 211 patients using a collarless double-taper cemented femoral component. The mean age of the patients was 72 years (30 to 90). The 137 long and 82 standard length stems were analysed separately. The mean follow-up was six years (2 to 18), and no patient was lost to follow-up. Survival of the long stems to re-revision for aseptic loosening at nine years was 98% (95% confidence interval (CI) 94 to 100), and for the standard stems was 93% (95% CI 85 to 100). At five years, one long stem was definitely loose radiologically and one standard stem was probably loose. Pre-operative femoral bone deficiency did not influence the results for the long stems, and corrective femoral osteotomy was avoided, as were significant subsidence, major stress shielding and persistent thigh pain. Because of these reliable results, cemented long collarless double-taper femoral components are recommended for routine revision THR in older patients.

Original cementless femoral stem for dysplastic hip: clinical results of HPF stem

We designed and developed the original cementless femoral stem (HPF) adapted to femurs of developmental dysplasia of the hip (DDH). Twenty-three arthroplasties using HPF were performed in 22 cases. The average age at the operation was 48.4 years. The average follow-up period was 6 years and 10 months. The average Harris Hip Score improved from 46.3 points preoperatively to 93.4 points postoperatively. All stems were classified as bone-ingrown or stable fibrous fixation. Clinically and radiologically excellent results proved the design concept of the HPF realized good fixation in the proximal femur with deformities of DDH. The surface treatment worked well for biological fixation even in clinically difficult cases with poor bone quality and/or complicated deformity of the femur of DDH.

The effect of partial or full weight bearing ambulation after cementless total hip arthroplasty

The clinical and radiographic results of 46 patients who underwent 50 consecutive primary total hip arthroplasties using a fully porous-coated collared femoral component were determined at a minimum of 2 years' follow-up. Twenty-four patients (25 hips) who were allowed to bear full weight immediately postoperatively were compared with a historical control group of 24 patients (25 hips) who were instructed to bear < or =50 lb of weight for 6 weeks. The average Harris hip score for the partial weight bearing group was 95 compared with 97 for the full weight bearing group. All femoral components in both groups had radiographic evidence of bone ingrowth fixation at the final follow-up. When solid initial fixation is obtained intraoperatively and radiographically using a fully porous-coated (AML) femoral component, it seems that bone ingrowth fixation reliably occurs whether or not a partial or full weight-bearing postoperative protocol is followed.

Bilateral cemented and cementless total hip arthroplasty

A subjective, clinical, and radiographic comparison was made between 140 primary cemented and cementless femoral components in 70 patients <50 years old who underwent bilateral simultaneous total hip arthroplasty. The average duration of follow-up was 7.8 years (range, 7-9 years). Hip scores were similar in both groups at the final follow-up. The prevalence of transitory thigh pain was 17% in the cementless group and 3% in the cemented group. No hip had subsidence or aseptic loosening of the acetabular or femoral components in either group. One cemented hip was revised for late infection, and 1 cementless hip was revised for recurrent dislocation. There was no difference in the incidence of osteolysis in the femur (9% in the cemented hip vs 13% in the cementless hip) and acetabulum (9% each) between the groups.

Morphometric examination of straight, tapered titanium stems: a retrieval study

Cementless straight, tapered rectangular cross section titanium stems have been used by the senior author since 1979. Thirty-four stems retrieved postmortem, after between 10 days and 15.2 years in situ, were studied morphometrically and histologically. Nineteen stems were first generation (1979-1986), with an incomplete sagittal taper and a mean surface roughness of 1 microm (Ra 1.23 +/- 0.3 microm); 15 stems were second generation after 1986, with a full biplane taper and a mean surface roughness of 4 microm (Ra 4.14 +/- 0.36 microm). Implant surface bony coverage was determined morphometrically in 10 segments of the stems, and expressed as a bone implant contact index. Histologically, there were no differences between implants with different levels of roughness. Morphometrically, the first-generation stems showed significant differences in coverage (distal > proximal); second-generation stems had a more uniform pattern. Stems retrieved early after arthroplasty had a mean bone implant contact index of 10%. The mean bone implant contact index showed attainment of maximum coverage by 5 years after arthroplasty, without additional apposition or loss thereafter. Patients younger than 65 years at arthroplasty had similar bone implant contact indices to patients 65 years or older; coverage in the six patients 80 years of age at retrieval did not differ from the rates in the other patients. Morphometry was able to provide objective evidence of design change effects. No differences in coverage were found in terms of times in situ, patient age at arthroplasty and at retrieval, and degree of stem surface roughness.