Host Bone Coverage Research Articles

[Translated article] Total hip arthroplasty with shelf acetabuloplasty in dysplastic coxarthrosis, mean follow-up of 7 years

IntroductionDevelopmental dysplasia of the hip is the cause of approximately one third of secondary coxarthrosis. Anatomy alterations make it difficult to place a total hip prosthesis in its anatomical position and for it to be stable in the long term; there are several techniques to achieve this goal. In the present work, we used autograft of the femoral head (shelf graft or reinforced roof), to improve the coverage of the acetabular component with favourable results. Materials and methodsSixteen cases were included in 14 patients with a diagnosis of developmental dysplasia of the hip (13 women and one man), the mean age was 44.3 years (range 35–68 years), with a mean follow-up of 7 years (range 1–15 years). All the cases were evaluated clinically and radiographically, to demonstrate the osseointegration of the graft and the functional results in the medium term. ResultsAll the acetabular components were placed in anatomical position (Ranawat technique), the mean percentage of host bone coverage was 54.53% (range 43.28–79.05%), obtaining additional coverage with the bone graft of 45.13%. Osseointegration of the graft of 100% at 12 weeks, resorption of the graft from the sixth month, stabilising in the third postoperative year. Only one case of dislocation is reported, no cases of infection, loosening, heterotopic ossification or revision. ConclusionThis procedure has shown good functional results in the medium term with 100% osseointegration, despite cases of severe bone resorption of the graft that does not compromise the stability of the prosthesis.

The Validation of Two-Dimensional and Three-Dimensional Radiographic Measurements of Host Bone Coverage in Total Hip Arthroplasty for Hip Dysplasia: A Comparison with Intra-Operative Measurements.

Several methods have been introduced to measure the host bone coverage of the acetabular component after total hip arthroplasty (THA). The aims of this study were (1) to validate two-dimensional- and three-dimensional-based host bone coverage measurements by comparing intra-operative measurements, and (2) to determine the minimum host bone coverage for achieving stable cup fixation after THA in hip dysplasia. The clinical outcomes of each patient were evaluated during their final follow-up period using the Harris Hip score (HHS). The coverage of the host bone was analyzed by comparing 2D-based, 3D-based, and intraoperative assessments. The mean HHS was increased significantly from 60.84 ± 14.21 pre-operatively to 93.13 ± 4.59 (p < 0.0001). The host bone coverage ratio measured intraoperatively was 83.67 ± 3.40%, while the ratio measured by 3D CT reconstruction was 82.72 ± 3.59%. There was a strong positive correlation between the intra-operative host bone coverage and the 3D-based one (r = 0.826, p < 0.0001). It is recommended that 3D-based measurements are used to evaluate the host bone coverage after THA in patients with hip dysplasia. In addition, achieving a minimum host bone coverage of 75% is recommended for the attainment of stable cup fixation.

Mean 14-year Outcomes of Hybrid Total Hip Arthroplasty Using Bulk Femoral Head Autografts for Acetabular Reconstruction

BackgroundWe aimed to evaluate the mean 14-year outcomes of hybrid total hip arthroplasty (THA) with cementless acetabular cups using bulk femoral head autografts in acetabular reconstruction and specify the radiological characteristics of cementless acetabular cups using this technique. MethodsThis retrospective study included 98 patients (123 hips) who underwent hybrid THA with a cementless acetabular cup using bulk femoral head autografts for bone deficiency in acetabular dysplasia and who were followed-up for a mean of 14 years (range, 10 to 19.6). The percentage of bone coverage index (BCI) and cup center–edge (CE) angles were evaluation radiologically of acetabular host bone coverage. The survival rate of the cementless acetabular cup and autograft bone ingrowth were assessed. ResultsThe survival rate with all revisions of cementless acetabular cups was 97.1% (95% confidence interval: 91.2 to 99.1). The autograft bone was remodeled or reoriented in all cases except in 2 hips where the bulk femoral head autograft collapsed. Radiological evaluation revealed a mean cup CE angle of −17.8° (range, −52 to −7°) and a BCI of 44.4% (range, 10 to 75.4%). ConclusionCementless acetabular cups using bulk femoral head autografts for bone deficiency of the acetabular roof remained stable even if the average BCI was 44.4% and the average cup CE angle was −17.8°. Cementless acetabular cups using these techniques showed good 10-year to 19.6-year outcomes and viabilities of graft bones.

Artroplastia total de cadera no cementada con techo armado en coxartrosis displásica, seguimiento medio de 7 años

Developmental dysplasia of the hip is the cause of approximately one third of secondary coxarthrosis. Anatomy alterations make it difficult to place a total hip prosthesis in its anatomical position and for it to be stable in the long term; there are several techniques to achieve this goal. In the present work, we used autograft of the femoral head (shelf graft or reinforced roof), to improve the coverage of the acetabular component with favorable results. Materials ad methodsSixteen cases were included in 14 patients with a diagnosis of developmental dysplasia of the hip (13 women and one man), the mean age was 44.3 years (range 35–68 years), with a mean follow-up of 7 years (range 1–15 years). All the cases were evaluated clinically and radiographically, to demonstrate the osseointegration of the graft and the functional results in the medium term. ResultsAll the acetabular components were placed in anatomical position (Ranawat technique), the mean percentage of host bone coverage was 54.53% (range 43.28–79.05%), obtaining additional coverage with the bone graft of 45.13%. Osseointegration of the graft of 100% at 12 weeks, resorption of the graft from the sixth month, stabilizing in the third postoperative year. Only one case of dislocation is reported, no cases of infection, loosening, heterotopic ossification or revision. ConclusionThis procedure has shown good functional results in the medium term with 100% osseointegration, despite cases of severe bone resorption of the graft that does not compromise the stability of the prosthesis.

Research status of acetabular reconstruction in Crowe type Ⅱ and Ⅲ developmental dysplasia of the hip

Developmental dysplasia of the hip (DDH) is a major cause of hip arthritis and ultimately total hip arthroplasty. Due to the dysplastic acetabulum, how to place the acetabular cup becomes a challenge in acetabular reconstruction for such patients. Especially in the acetabula classified as Crowe typeⅡand type Ⅲ, the dislocation of the femoral head causes bone defects above the true acetabulum, which will affect the stability of the acetabular cup when the acetabular reconstruction is performed at the true acetabulum. Many acetabular reconstruction methods such as bone grafting, the use of small acetabular cups, socket medialization technique, and high hip center technique are used to increase the host bone coverage of the cup. However, each method has its own shortcomings that can not be ignored so that there is no unified conclusion on the acetabular reconstruction methods for Crowe typeⅡand type Ⅲ hip dysplasia. This article summarized and evaluated various reconstruction methods in combination with the acetabular morphology of DDH, and put forward the research direction in the future.

Segmental uncoverage ratio analysis of Crowe type-IV developmental dysplasia of the hip via 3-dimensional implantation simulation

BackgroundTo study the segmental uncoverage ratio (UCR) of a 44-mm cup model placed in a true acetabulum of Crowe type-IV developmental dysplasia of the hip via 3-Dimensional (3D) implantation simulation.MethodsQualified CT imaging data of 26 patients (involving 30 hips) with Crowe type-IV DDH were imported into Mimics software for reconstruction. Then a 44-mm eggshell cup model was placed in a true acetabulum. First, total uncoverage ratio (TUCR) was measured. Then the virtual cup was divided into 4 segments according to the quadrant setting of the true acetabulum, i.e., anterior-superior (A-S) segment, anterior-inferior (A-I) segment, posterior-superior (P-S) segment and posterior-inferior (P-I) segment. The UCRs of the aforementioned segments were measured, i.e., anterior-superior uncoverage ratio (A-SUCR), anterior-inferior uncoverage ratio (A-IUCR), posterior-superior uncoverage ratio (P-SUCR) and posterior-inferior uncoverage ratio (P-IUCR). The acetabular height and anterior-posterior diameter on the 3-D model were also calculated. Statistic analyses were performed by using SPSS software package.ResultsTUCR was 0.2958 ± 0.1003 (95% [CI], 0.1020 to 0.5400) in this cohort of Crowe Type-IV hips. P-SUCR had the greatest value among all the segmental UCRs (0.1012 ± 0.0435, 95% confidence interval [CI],0.0152 to 0.1914) and the most significant positive correlation with TUCR (Pearson correlation = 0.889, p < 0.01. Linear regression R2 = 0.791). Similarly, P-IUCR and A-SUCR showed a significant positive correlation with TUCR. However, A-IUCR exhibited no correlation with either total or other segmental UCRs. P-SUCR was found to bear significant positive correlation with P-IUCR (pearson correlation = 0.644, p < 0.01. Linear regression R2 = 0.415). Acetabular height and A-P diameter were not correlated with TUCR.ConclusionImplantation of a 44-mm cup into Crowe type IV acetabulum is feasible and could achieve acceptable host bone coverage in most of the cases. P-SUCR contributed most to TUCR. TUCR had no linear relationship with the size of the host acetabulum, suggesting that the pre-operative plan should be individualized.

Three-Dimensional Host Bone Coverage Required in Total Hip Arthroplasty for Developmental Dysplasia of the Hip and Its Relationship With 2-Dimensional Coverage

BackgroundIn total hip arthroplasty, the minimum host bone coverage required on the cup for stable fixation has been previously reported; however, the coverage was generally evaluated on a 2-dimensional (2D) image and 3-dimensional (3D) coverage has not been well described. MethodsWe used postoperative computed tomography images to retrospectively measure 3D cup coverage in 151 hips with developmental dysplasia of the hip that underwent primary total hip arthroplasty. The aims were to (1) determine the minimum requirement of the 3D coverage for stable cup fixation; (2) evaluate the relationship between 2D and 3D coverage; and (3) identify the factors associated with 2D-3D discrepancy, defined as follows: 2D-3D discrepancy = 2D coverage−3D coverage. ResultsAll cups showed stable fixation as demonstrated by bone ingrowth with an average postoperative period of 48 months. The minimum 3D coverage was 61.2%, with a mean value of 77.1% ± 6.7% and maximum value of 97.6%. We found a significant positive but poor relationship between 3D and 2D coverage (bone coverage index; r = 0.30). Consequently, the 2D-3D discrepancy varied greatly, with a mean value of −1.6% ± 12.3% (range, −36.5% to 32.2%). Multiple linear regression analyses confirmed that lower cup center and anterior tilt of the pelvis relative to the computed tomography table were independent factors associated with increasing 2D-3D discrepancy. ConclusionThis study showed that 2D coverage, measured on a projected image, carries a risk of overestimation, especially in hips with the aforementioned features.

Long-term retrospective study on the placement of the cementless acetabular cup and clinical outcomes in patients undergoing femoral head autografting for hip dysplasia and total hip arthroplasty.

Placement of acetabular cup in the dysplastic hip is a challenging procedure. Using bulk femoral headautograft to increase the bony coverage of the cup is one of the techniques, which have been described. Theimpact of cup position on cup and autograft survival is a controversial issue. We aimed to determine whether the position of cementless acetabular cup used in conjunction with femoral head autograft in dysplastic hips affected the autograft-host incorporation with its final radiographic appearance and the cup survivorship into the second decade. Thirty-eight dysplastic hips with varying Crowe types in 31 patients (30 women and one man) were included. The mean age was 47 years (range, 29-64 years) and the mean follow-up was 20.3 years (range, 14.8-25.9 years). The initial postoperative and final radiographs were evaluated. The survival rate of the cups was analysed using Kaplan-Meier statistics and the log-rank test. Multivariate analysis was used to evaluate the effect of variables (Crowe type, radiographic initial host bone coverage over the cup and position of the cup) on survivorship. The acetabular cups were positioned anatomical in 27/38 hips according to Ranawat measurement technique. Trabecular bridging at graft-host interface was seen in all cases at an average 22.1 months. Neither acetabular cup position nor initial host bone coverage over acetabular cup less than 50% had any significant effect on either cup survival or final radiographic appearance of the graft. The 20-year cup survival rate without aseptic revision was 66% (95 CI, 52%-84%). No revision was performed due to graft resorption. Twenty-year survival rate of the cementless cup combination with femoral head autograft showed no significant differences whether it was placed at high or anatomic hip centre. The final radiographic appearance of the autograft was not affected from either the cup location or the initial radiographic horizontal host bone coverage.

Tantalum Components in Difficult Acetabular Revisions Have Good Survival at 5 to 10 Years: Longer Term Followup of a Previous Report.

The best method for acetabular revisions in patients with severe bone loss remains controversial; typical approaches include jumbo cups, cages, cup-cages, and custom components. Tantalum (TM) components have good results at midterm followup, but the longer term survival and complications are not available. We previously reported on a series of such reconstructions; here we provide additional followup on that group along with a larger study cohort. (1) What is the survival at a minimum followup of 5 years of these components implanted in difficult revisions and what is the mechanism of failure? (2) What is the most common complication of these reconstructions, and what hip scores did these patients achieve? Between 2001 and 2010, one surgeon performed 150 acetabular revisions, of which 74 (49%) were done using TM components. The general indication for use of these devices was the surgeon's perception that there was sufficient bone loss to place the reconstruction at a high risk of mechanical failure (generally Paprosky Type 3 or 4 or lower Paprosky type with < 50% host bone coverage or morbid obesity). No cages were used during this time. Fifteen patients died and 11 were lost or did not return, leaving 48 hips (46 patients) with a mean followup of 8 years (range, 5-14 years). Of these, 39 were reported on in our previous series, and nine are new in the present series; the overall group here has an additional median of 5 years followup (range, 3-7 years). Five hips had six augments placed to obtain stability. Patients were evaluated by the Harris hip score and standard radiographs; survivorship was estimated using the cumulative incidence competing risks survival analysis. The primary outcome was fixation and survival of the TM component and the secondary outcome was complications. Cumulative incidence competing risks estimate survival free from aseptic loosening was 92% at 10 years (95% confidence interval [CI], 0.81-0.98). Dislocation, the most common complication, occurred in seven of 48 (15%) patients, and five of 48 (10%) had a reoperation for it. Survival free from any reoperation was 84% at 10 years (95% CI, 0.72-0.92). The Harris hip score improved from a mean of 50 points (SD 17) before surgery to 85 points (SD 10; p < 0.001) at latest followup. Given the findings of this study, TM components appear to provide durable fixation at midterm followup in complex acetabular revisions. Steps to minimize dislocation, the most frequent complication of these revisions, may include the routine use of larger femoral heads. Future studies likely will need to be multisurgeon or multicenter and should evaluate different techniques and components for long-term fixation and the prevention of dislocation. Level IV, therapeutic study.

Is high hip center technique an acceptable choice for total hip arthroplasty of the developmental dysplasia of the hip?

Total hip arthroplasty (THA) is a successful method to treat osteoarthritis secondary to the developmental dysplasia of the hip (DDH). As anatomic deformity of acetabulum, anatomic hip center placing of the socket may lead insufficient host bone coverage, therefore, high hip center (HHC) technique is an alternative choice. Location of the hip rotation center can be referenced by inter teardrop line, the highest point of the obturator foramen, summit of the iliac crests, ischial tuberosities and other anatomic landmarks. The HHC technique is supposed to increase host bone coverage of socket without structural bone grafts, simplify surgical procedures, reduce anesthetic and surgical time, conserve adequate healthy bone stock for revision, however, it leads to insufficiency of the abductor muscles, is speculated to increase the hip load, lower the range of hip flexion and internal rotation (IR). Loosening rates and polyethylene wear vary in different studies. Concerning about these factors, HHC technique is acceptable while center of rotation located at a horizontal level with distance less than 35 mm from the inter teardrop line, moreover, medialization of these HHC reconstructions is suggested.

Bone Graft Augmentation for Severe Glenoid Bone Loss in Primary Reverse Total Shoulder Arthroplasty: Outcomes and Evaluation of Host Bone Contact by 2D-3D Image Registration.

Background:The treatment of patients with severe glenoid bone loss using reverse total shoulder arthroplasty (RSA) is challenging because of the difficulty in obtaining glenoid fixation. The outcomes following primary RSA with structural bone-grafting for severe glenoid bone loss and the amount of native bone support necessary to achieve clinical improvement are unclear.Methods:We reviewed functional outcomes (American Shoulder and Elbow Surgeons [ASES] score, Simple Shoulder Test [SST], visual analog scale [VAS] for pain and function, patient satisfaction, and range of motion) for 57 patients who were treated with a primary RSA and glenoid bone-grafting for severe glenoid bone loss. Three glenoids were classified as type A2; 2, as type B2; and 2, as type C, according to the Walch classification; 16 glenoids, as grade E1; and 19, as grade E3, according to the Sirveaux classification; 9 glenoids, as grade 3, according to the Levigne classification; and 6 were unable to be classified. For the 44 patients with adequate preoperative computed tomographic (CT) data and postoperative radiographs, we evaluated native bone contact under the glenoid baseplate by matching the projected shape of the implant and scapula from the postoperative radiographs with a generated 3-dimensional (3D) model of the preoperative scapula. We then analyzed functional outcomes in relation to native bone support of the baseplate.Results:At a mean of 46 months (minimum, 24 months), the patients demonstrated significant improvements in function, motion, and pain (change in the ASES total score = 38.6, change in SST = 5.4, change in forward elevation = 72.4°, change in abduction = 67.7°, change in external rotation = 24.3°, and change in VAS pain score = −4.6; p < 0.001 for all). On the basis of the generated 3D model, the baseplate contact to host bone was a mean (and standard deviation) of 17% ± 12% (range, 0% to 50%). There was no significant correlation between host bone coverage and change in the ASES score (p = 0.51) for the 44 patients included in this analysis. There were 4 major complications (7%) in the study group but no glenoid baseplate failures.Conclusions:Glenoid bone-grafting in a primary RSA in a shoulder with severe bone loss produces good functional outcomes that do not correlate with the degree of native bone contact under the baseplate. We had observed no glenoid component failures at the time of writing.Level of Evidence:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Three-Dimensional Host Bone Coverage in Total Hip Arthroplasty for Crowe Types II and III Developmental Dysplasia of the Hip

BackgroundRecommendations for minimum cup coverage based on anteroposterior radiographs are widely used as an intraoperative guide in total hip arthroplasty for patients with developmental dysplasia of the hip. The purpose of this study was to examine the validity of two-dimensional (2D) measurement of coverage with three-dimensional (3D) coverage and to identify parameters for determining the 3D coverage during surgery. MethodsWe developed a technique to accurately reproduce the intraoperative anatomic geometry of the dysplastic acetabulum and measure the 3D cup coverage postoperatively. With this technique, we retrospectively analyzed the difference and correlation between 2D and 3D measurements of native bone coverage in 35 patients (45 hips) with Crowe II or III DDH. Linear regression analysis was performed to examine the intraoperative parameters related to coverage. The mean follow-up period was 7.64 years (range, 6.1-9.5 years). ResultsThere was a significant difference and a fair correlation between 2D and 3D measurements. The 2D measurement underestimated the 3D cup coverage by approximately 13%. An excellent linear relationship was noted between the 3D coverage/uncoverage and the height of the uncovered portion (R2 = 0.8440, P < .0001). There was no case of loosening or revision during the follow-up. ConclusionCurrent minimum cup coverage recommendations based on 2D radiograph measurements should not be used as a direct intraoperative guide. The height of the uncovered portion is a useful parameter to determine the 3D coverage during surgery.

Paper #35 - 2D/3D image registration to determine host bone coverage of glenoid side reverse shoulder implants

Paper #35 - 2D/3D image registration to determine host bone coverage of glenoid side reverse shoulder implants

Posterosuperior Placement of a Standard-Sized Cup at the True Acetabulum in Acetabular Reconstruction of Developmental Dysplasia of the Hip With High Dislocation

BackgroundWe sought to evaluate posterosuperior placement of the acetabular component at the true acetabulum during acetabular reconstruction in patients with Crowe type-IV developmental dysplasia of the hip. MethodsUsing pelvic computed tomography and image processing, we developed a two-dimensional mapping technique to demonstrate the distribution of preoperative three-dimensional cup coverage at the true acetabulum, determined the postoperative location of the acetabular cup, and calculated postoperative three-dimensional coverage for 16 Crowe type-IV dysplastic hips in 14 patients with a mean age of 52 years (33-78 years) who underwent total hip arthroplasty. Mean follow-up was 6.3 years (5.5-7.3 years). ResultsOn preoperative mapping, the maximum three-dimensional coverage using a 44-mm cup was 87.31% (77.36%-98.14%). Mapping enabled the successful replacement of 16 hips using a mean cup size of 44.13 mm (42-46 mm) with posterosuperior placement of the cup. Early weight-bearing and no prosthesis revision or loosening during follow-up were achieved in all patients. The postoperative two-dimensional coverage on anteroposterior radiographs and three-dimensional coverage were 96.15% (89.49%-100%) and 83.42% (71.81%-98.50%), respectively. ConclusionThis technique may improve long-term implant survival in patients with Crowe-IV developmental dysplasia of the hip undergoing total hip arthroplasty by allowing the use of durable bearings, increasing host bone coverage, ensuring initial stability, and restoring the normal hip center.

The use of fibre-based demineralised bone matrix in major acetabular reconstruction: surgical technique and preliminary results

Acetabular osteolysis associated with socket loosening is one of the main long-term complications of total hip arthroplasty. In case of major bone loss, where <50% host bone coverage can be obtained with a porous-coated cementless cup, it is generally agreed that a metal ring or cage in association with a cemented component and allograft bone should be used. In order to promote allograft bone consolidation and incorporation, we have associated demineralised bone matrix (DBM, Grafton® A Flex) to the construct ion. Here we describe the technical details of major acetabular reconstruction using the Kerboull acetabular reinforcement device with allograft bone and DBM. This device has a hook that must be placed under the teardrop of the acetabulum and a plate for iliac fixation. The main advantages of this device are help in restoring the normal centre of hip rotation, guiding the reconstruction and partially unloading the graft. The Kerboull acetabular reinforcement device has provided a 92% survival rate free of loosening at 13-year follow-up in a consecutive series of 60 type III and IV deficiencies. Our preliminary results using DBM indicate faster allograft consolidation and remodelling.

The Results of a Press-Fit-Only Technique for Acetabular Fixation in Hip Dysplasia

The purpose of the present study was to evaluate the 6- to 11-year follow-up results of hemispherical porous-coated cups implanted into dysplastic hips using press-fit technique without screws focusing on the amount of host bone coverage. There were 87 patients who underwent 98 primary total hip arthroplasties. Bony coverage was measured as the angle between the vertical line and the line drawn from the cup center to the lateral edge of the acetabulum, which was named the cup center-edge angle (cup-CE angle). All 98 cups were judged to be bone ingrown. The minimum cup-CE angle was 8.4° (mean, 26.3°). Bone-cup contact of more than 8.4° of the cup-CE angle was large enough for press-fit cups to resist superior directed loads during this follow-up period.

Grit-blasted and hydroxyapatite-coated total hip arthroplasty: an 11- to 14-year follow-up study

AbstractWe report long-term results of the first clinical trial of hydroxyapatite-coated total hip arthroplasty conducted in Japan. The hemispherical cup and the straighttapered stem were made of titanium alloy with a grit-blasted, hydroxyapatite-coated surface. The surface roughness before and after hydroxyapatite coating was 1.4μm and 3.4μm, respectively. Thirty-three patients (35 hips) were followed prospectively; of these, 1 patient was lost to follow-up, 5 were deceased at the latest follow-up, and 27 were followed for 11 to 14 years. Two cups and one stem (two patients) were revised. Survivorship, with radiological acetabular loosening as the endpoint, was 62.3% at 14 years. At the latest radiological follow-up, stable fixation with bone ongrowth was achieved in 46% of the acetabular cups and 89% of the femoral stems. Acetabular cups with host bone coverage of less than 60% had a high rate of failure. The suboptimal result of the hydroxyapatite-coated smooth cup indicates that porous coatings under the hydroxyapatite coating would be beneficial for hydroxyapatite-coated total hip implants, especially for the acetabular components.

Host bone coverage requirements for press-fit acetabular cup fixation. 3D-CT analysis

Host bone coverage requirements for press-fit acetabular cup fixation. 3D-CT analysis

Reinforcement rings with hook in acetabular reconstruction

Acetabular osteolysis associated with socket loosening is one of the main long-term complications of total hip arthroplasty. In the case of major bone loss where less than 50% host bone coverage can be obtained with a porous-coated cementless cup, it is generally agreed that a metal ring in association with a cemented component and allograft bone should be used. Herein we describe the technical details of the use of the Kerboull acetabular reinforcement device and the GAP cup. Both these devices have a hook that has to be placed under the teardrop of the acetabulum and a plate for iliac fixation. The main advantages of these devices are their help in restoring the normal hip center of rotation, guiding the reconstruction, and partially unloading the graft. The Kerboull acetabular reinforcement device has provided a 92% survival rate free of loosening at 13-year follow-up in a consecutive series of 60 type III and IV deficiencies.