Harrington Procedure Research Articles

The Modified Harrington Procedure for Metastatic Peri-Acetabular Bone Lesion Using a Novel Highly Porous Titanium Revision Shell with Long Lever Arm Screw.

Background and Objectives: Peri-acetabular metastases often lead to significant pain and functional impairment. Surgical interventions, including the Harrington procedure, aim to address these challenges. This study evaluates a modified Harrington procedure using the MUTARS® PRS® (Pelvic Revision Shell) with an 8 mm fixation screw for severe acetabular defects resulting from metastatic lesions. Materials and Methods: Retrospective analysis of 12 patients treated between January 2020 and December 2023 was conducted. The procedure involved using the novel MUTARS® PRS® with an 8 mm in diameter dome screw (length 70-100 mm). Outcome measures included implant positioning changes, complication rates, functional outcomes, implant longevity, and patient survival. Radiological assessments were performed postoperatively, with follow-ups at 3, 6, 12 months, and annually thereafter. Results: Average follow-up was 15 ± 11 months, with 67% patient survival at 1 year and 44% at 2 years. Implant survivorship remained 100%. Harris Hip Score improved significantly from 37 ± 22 preoperatively to 75 ± 15 at the last follow-up. No revisions involving implant components were reported. Complications occurred in 5 of 12 patients. Overall, PRS® demonstrates effective osseous ingrowth, high primary stability, immediate full weight-bearing, and low complication rates. Conclusions: PRS® integrates facilitating osseous ingrowth for preferable long-term outcomes, while efficiently transmitting the weight-bearing load to the intact aspect of the pelvis using a long 8 mm lever screw, enhancing the primary stability of the construct. It proves to be an effective and reproducible technique for managing destructive metastatic lesions of the acetabulum and peri-acetabular region, even in irradiated bone.

Modifikovaná Harringtonova operace v terapii rozsáhlých nádorových defektů acetabula

PURPOSE OF THE STUDY The increasing prevalance of patients with metastatic bone cancer and their improved survival puts more emphasis on the quality of treatment of bone metastases. Although most pelvic lesions are treated non-operatively, extensive destruction of the acetabular segment poses a therapeutic challenge. A potential treatment option may be the modified Harrington procedure. MATERIAL AND METHODS At our department, this surgical procedure has been opted for in 14 patients (5 men and 9 women) since 2018. The mean age at the time of surgery was 59 years (range 42 to 73). Twelve patients suffered from metastatic cancer, one patient had a fibrosarcoma metastasis and one female patient presented with aggressive pseudotumor. Radiological and clinical followup of the patients was performed. Pain was assessed using the Visual Analogue Scale, and the Harris Hip Score and the MSTS score were used to evaluate the functional outcome. The paired samples Wilcoxon test was used to analyze the statistical significance of the difference. RESULTS The mean follow-up period was 25 months. At the time of assessment, ten patients were alive with the mean follow-up of 29 months (range 2 to 54 months) and four patients had died of cancer progression, with the mean follow-up being 16 months. No perioperative death or mechanical failure were reported. One female patient developed a hematogenous infection during febrile neutropenia, which was successfully managed with early revision and implant preservation. Statistically, a significant improvement in the MSTS (median 23) and HHS (median 86) functional scores compared to the preoperative values (MSTS median 2, p<0.01, r-effect size = 0.6; HHS preop median 0, p<0.005, r-effect size = -0.7) was observed. There was also a statistically significant reduction in pain (VAS postoperative median 1, VAS preoperative median 8, p<0.01, r-effect size = -0.6). All patients were capable of independent ambulation after the surgery, nine patients walked without support. DISCUSSION There are not many alternatives to this surgical procedure. Apart from non-operative palliative treatment, the options include ice cream cone prostheses or customized 3D implants which are, impractical in terms of time and cost. Our results are comparable to other studies, confirming the reproducibility and reliability of the method. CONCLUSIONS The Harrington procedure is an efective method for management of large acetabular tumor defects with good functional outcomes, an acceptable perioperative risk and a low risk of failure in the medium term, thus suitable also for patients with good cancer prognosis. Key words: umor, metastasis, acetabulum, pelvis, Harrington, reconstruction.

Functional and Survival Outcomes of Patients following the Harrington Procedure for Complex Acetabular Metastatic Lesions.

Background: The Harrington surgical technique makes it possible to manage complex, extensive bone lesions using pins and cement to consolidate bone for acetabular cup positioning. However, it may be associated with a high reoperation rate, and the functional results of this surgery are not precisely described in the literature. Methods: In a monocentric retrospective study including all patients operated on using the Harrington procedure associated with THA between 2005 and 2020, we aimed to assess preoperative and postoperative function, reoperation-free survival, and overall survival. Results: Functional improvement was significant for Parker scores (preoperative: 3.6 ± 2.0; 6-month follow-up: 6.6 ± 3.2; 12-month follow-up: 7.6 ± 2.1) and Musculoskeletal Tumor Society (MSTS) scores (preoperative: 31.1 ± 16.2%; 6-month follow-up: 67.7 ± 30.6%; 12-month follow-up: 82.4 ± 24.0%). Of the 21 patients included, the reoperation-free survival rate was 76.1% [CI 95%: 58.1–99.7] at six and twelve months, with the main complications being pin migration (50.0%) and infection (25%). The patient overall survival rate was 76.2% [95% CI: 59.9–96.7] at six months and 61.9% [95% CI: 59.9–96.7] at 12 months. Discussion: These results underlined significant functional improvements following a conventional Harrington procedure, with acceptable reoperation rates.

Outcomes of Hip Reconstruction for Metastatic Acetabular Lesions: A Scoping Review of the Literature

(1) Background: Management of metastatic periacetabular lesions remains a challenging area of orthopaedics. This study aims to evaluate and summarize the currently available reconstructive modalities, including their indications and outcomes. (2) Methods: A scoping review was carried out in accordance with PRISMA guidelines. Medline, EMBASE, and Cochrane were searched for relevant articles. (3) Results: A total of 18 papers met inclusion criteria encompassing 875 patients. The most common primary malignancy was breast (n = 230, 26.3%). Reconstruction modalities used were total hip arthroplasty (n = 432, 49.1%), the Harrington procedure (n = 374, 42.5%), modular hemipelvic endoprotheses (n = 63, 7.2%) and a reverse ice-cream cone prosthesis (n = 11, 1.25%). (4) Conclusions: Advances in implant design including use of dual mobility or flanged cups, tantalum implants, and modular hemipelvic endoprostheses allow for larger acetabular defects to be addressed with improved patient outcomes. This armamentarium of reconstruction options allows for tailoring of the procedure performed depending on patient factors and extent of periacetabular disease.

Emerging Concepts in the Surgical Management of Peri-Acetabular Metastatic Bone Disease.

The pelvis is a common site of metastatic bone disease. Peri-acetabular lesions are particularly challenging and can cause severe pain, disability and pathologic fractures. Surgical management of these lesions has historically consisted of cementoplasty for contained lesions and Harrington reconstructions for larger, more destructive lesions. Due to the limitations of these procedures, a number of novel procedures have been developed to manage this challenging problem. Percutaneous techniques—including acetabular screw fixation and cementoplasty augmented with screws—have been developed to minimize surgical morbidity. Recent literature has demonstrated a reliable reduction in pain and improvement in function in appropriately selected patients. Several adjuncts to the Harrington procedure have been utilized in recent years to reduce complication rates. The use of constrained liners and dual mobility bearings have reduced the historically high dislocation rates. Cage constructs and porous tantalum implants are becoming increasingly common in the management of large bony defects and destructive lesions. With novel and evolving surgical techniques, surgeons are presented with a variety of surgical options to manage this challenging condition. Physicians must take into account the patients’ overall health status, oncologic prognosis and anatomic location and extent of disease when developing an appropriate surgical plan.

Surgical Treatment and Proposed Modified Classification for Harrington Class III Periacetabular Metastases.

ObjectivesThis study aims to: (i) evaluate the outcome of patients with Harrington class III lesions who were treated according to Harrington classification; (ii) propose a modified surgical classification for Harrington class III lesions; and (iii) assess the efficiency of the proposed modified classification.MethodsThis study composes two phases. During phase 1 (2006 to 2011), the clinical data of 16 patients with Harrington class III lesions who were treated by intralesional excision followed by reconstruction of antegrade/retrograde Steinmann pins/screws with cemented total hip arthroplasty (Harrington/modified Harrington procedure) were retrospectively reviewed and further analyzed synthetically to design a modified surgical classification system. In phase 2 (2013 to 2019), 62 patients with Harrington class III lesions were classified and surgically treated according to our modified classification. Functional outcome was assessed using the Musculoskeletal Tumor Society (MSTS) 93 scoring system. The outcome of local control was described using 2‐year recurrence‐free survival (RFS). Owing to the limited sample size, we considered P < 0.1 as significant.ResultsIn phase 1, the mean surgical time was 273.1 (180 to 390) min and the mean intraoperative hemorrhage was 2425.0 (400.0 to 8000.0) mL, respectively. The mean follow‐up time was 18.5 (2 to 54) months. Recurrence was found in 4 patients and the 2‐year RFS rate was 62.4% (95% confidence interval [CI] 31.6% to 93.2%). The mean postoperative MSTS93 score was 56.5% (20% to 90%). Based on the periacetabular bone destruction, we categorized the lesions into two subgroups: with the bone destruction distal to or around the inferior border of the sacroiliac joint (IIIa) and the bone destruction extended proximal to inferior border of the sacroiliac joint (IIIb). Six patients with IIIb lesions had significant prolonged surgical time (313.3 vs 249.0 min, P = 0.022), massive intraoperative hemorrhage (3533.3 vs 1760.0 mL, P = 0.093), poor functional outcome (46.7% vs 62.3%, P = 0.093), and unfavorable local control (31.3% vs 80.0%, P = 0.037) compared to the 10 patients with IIIa lesions. We then modified the surgical strategy for two subgroup of class III lesions: Harrington/modified Harrington procedure for IIIa lesions and en bloc resection followed by modular hemipelvic endoprosthesis replacement for IIIb lesions. Using the proposed modified surgical classification, 62 patients in the phase 2 study demonstrated improved surgical time (245.3 min, P = 0.086), intraoperative hemorrhage (1466.0 mL, P = 0.092), postoperative MSTS 93 scores (65.3%, P = 0.067), and 2‐year RFS rate (91.3%, P = 0.002) during a mean follow‐up time of 19.9 (1 to 60) months compared to those in the phase 1 study.ConclusionThe Harrington surgical classification is insufficient for class III lesions. We proposed modification of the classification for Harrington class III lesions by adding two subgroups and corresponding surgical strategies according to the involvement of bone destruction. Our proposed modified classification showed significant improvement in functional outcome and local control, along with acceptable surgical complexity in surgical management for Harrington class III lesions.

A modified Harrington technique for periacetabular reconstruction in advanced metastatic bone disease and a discussion of alternative treatment options.

Management of periacetabular lesions involves complex clinical decision making. The modified Harrington procedure with total hip arthroplasty can recreate pelvic stability with a cement rebar construct as well as a functional hip. This study analyzes the modified Harrington procedure to assess construct longevity and patient outcomes. We queried a prospectively maintained database to identify all patients at a large academic medical center from 2017 to 2019 with periacetabular metastatic disease treated with a modified Harrington. Medical records were reviewed and complications, patient outcomes, Musculoskeletal Society Tumor (MSTS) scores, and implant survival were recorded. A total of nine patients were treated with the modified Harrington between 2017 and 2019. At maximum follow- up there were zero revisions or longterm complications. The mean preoperative MSTS score was 2.2 (range, 0-18), compared to the mean postoperative MSTS score of 17.7 (range, 9-25) recorded at a mean 4 (range, 1-30) months following surgery (p<0.001). The modified Harrington technique total hip technique for reconstruction in periacetabular metastatic bone disease is a safe procedure with effective symptom relief, improvement in function, and excellent implant survivorship.

The long-term outcomes of modified Harrington procedure using antegrade pins for periacetabular metastasis and haematological diseases.

The aim of this study was to present the long-term surgical outcomes, complications, implant survival, and causes of implant failure in patients treated with the modified Harrington procedure using antegrade large diameter pins. A cohort of 50 consecutive patients who underwent the modified Harrington procedure for periacetabular metastasis or haematological malignancy between January 1996 and April 2018 were studied. The median follow-up time for all survivors was 3.2 years (interquartile range 0.9 to 7.6 years). The five-year overall survival rate was 33% for all the patients. However, implant survival rates were 100% and 46% at five and ten years, respectively. Eight patients survived beyond five years. There was no immediate perioperative mortality or complications. A total of 15 late complications occurred in 11 patients (22%). Five patients (10%) required further surgery to treat complications. The most frequent complication was pin breakage without evidence of acetabular loosening (6%). Two patients (4%) underwent revision for aseptic loosening at 6.5 and 8.9 years after surgery. Ambulatory status and pain level were improved in 83% and 89%, respectively. The modified Harrington procedure for acetabular destruction has low complication rates, good functional outcome, and improved pain relief in selected patients Cite this article: Bone Joint J 2019;101-B:1557-1562.

Various Surgical Treatment of Hemophilic Pseudotumor : A Case Series.

Bleeding episodes in severe hemophilia may occur more frequently and spontaneously after mild trauma or daily activities. An inadequate treatment of that bleeding in hemophilia may result in pseudotumor, usually in the muscle adjacent to the bone. We reported haemophilic pseudotumor treated with various surgical interventions. This study was conducted inthe Department of Orthopaedic and Traumatology at a government hospital over a period of 7 years(2010 -2017). Patients Perioperative management was done in accordance with the Integrated Hemophilia Team of our institution protocol.Diagnosis and management planning of hemophilic pseudotumor was confirmed via Integrated HemophiliaTeam meeting. After the surgery, all patients were asked to come for routine follow up. We reported six Haemophilia-A patients with pseudotumor in the pelvis, proximal femur and lower leg. One case in pelvic bone underwent hematoma evacuation, acetabular reconstruction using the Harrington procedure, and total hip arthroplasty.Two cases, a case in the proximal femur and another case in the distal fibula, were treated with amputation, other two cases, one was soft tissue psedotumor in the pelvic region and was treated by hematoma evacuation, and the remaining casewas managed with wide excision and followed by defect closure. Surgery is a preferable treatment for pseudotumors that have been present for years.It's associated with the best outcomes especially when selected as the primary line ofwith preventable and manageable bleeding complication. As previously published by many authors, this paper confirms that surgical excision is the treatment of choice but should only be carried out in major hemophilia centers by a multidisciplinary surgical team.

Oncological, surgical and functional results of the treatment of patients after hemipelvectomy due to metastases

Metastatic lesions localized in the pelvis cause pain, pathological fractures and decrease quality of patients life. Limited data are avaliable to compare the oncological, surgical and functional outcomes after different surgeries in patients with metastatic pelvic tumors. Most of the works presents the results of hemipelvectomy performed in patients with primary malignant bone tumors. The objectives of this study were to assess the outcome of patients after internal hemipelvectomy due to cancer metastases. Over the period 2010–2015 at the Department of Orthopaedic Oncology in Brzozow, 34 patients with metastases to the pelvis were treated. This study group comprised of 21 men and 13 women. The mean age was 67 (range: 51–79) for men and 56 (range: 41–77) for women. The majority of the treated patients suffered from myeloma (12 patients) and breast cancer (8 patients). Following the Enneking system classification guidelines, tumours were found in zone I (5 cases), zone II (18 cases), zone III (4 cases). Tumour involvement of both zones (II and III) considered 7 patients. The following resections were accomplished: wide in 11 cases, marginal in 17 cases, and intralesional in 6 cases. 18 patients were postoperatively treated with 8 Gy single-dose radiotherapy. 25 patients underwent bone reconstruction using either Lumic prostheses (9 cases) or the Harrington technique (16 cases). The mean follow-up period was 2.1 years (range: 1.2–6 years). The analysis covered patients’ survival, number of local recurrences, functional results and effectiveness of surgical treatment, considering the type, number and reason of complications. Eight patients died. Overal survival calculated with Kaplan- Meier curve was 48.2% for 34 patients. Mean survival was 3.85 years. There were no statistically significant differences in overall survival depending on the type of metastasis resection. In this group, local tumour recurrences concerned 6 patients. The extent of tumour resection and the use of postoperative radiotherapy were statistically significantly related to local recurrences. Functional results were better in a group of patients without reconstruction. Postoperative VAS score was 2.7, Karnofsky status 71 and MSTS 23(86%). After Lumic prostheses implantation VAS score was 3.4, Karnofsky status 65 and MSTS 19(63%). The worst results were observed after Harrington procedure. We noticed 9 perioperative complications in 6 (18%) of patients. Most frequently, the problems included impaired wound healing due to infection (4 patients) and dislocation of Lumic prosthesis (2 patients). The frequency of local recurrences after hemipelvectomies is related to the radicality of tumour resection and the postoperative application of radiotherapy. Survival time depends on the type and stage of cancer and does not depend on the type of tumour resection. The best functional results were obtained in patients after type I resection followed by no reconstruction of the bone. Lumic prosthesis implantation gave better results than Harrington procedure.

A case of modified Harrington procedure for advanced metastatic destruction of acetabulum

A case of modified Harrington procedure for advanced metastatic destruction of acetabulum

Reconstruction of metastatic acetabular defects using a modified Harrington procedure

Background and purpose — Metastases engaging the acetabulum result in significant disability. We investigated the outcome after curettage and reconstruction of the defect with a protrusio cage, retrograde screws, and a cemented total hip arthroplasty.Patients and methods — We retrospectively identified 70 consecutive patients who were surgically treated for metastatic disease of the acetabulum between 1995 and 2012 using the above technique. The type of primary tumor, extent of the disease, degree of acetabular erosion, and type of implant used were identified. Patient and implant survival, complications, and functional outcome were recorded.Results — There were no mortalities in the perioperative period (30 days after surgery). Median overall patient survival was 12 months. Prosthesis survival was 92% at 1 year and 89% at 5 years. One third of the patients suffered a complication, the most frequent one being dislocation. The functional outcome was good. Multiple skeletal or visceral metastases and specific types of cancer were associated with poor patient survival.Interpretation — Reconstruction of metastatic acetabular defects using a protrusio cage stabilized with retrograde screws and a cemented total hip arthroplasty is a safe procedure that provides efficient relief of symptoms. Patients with extensive disease, especially when diagnosed with specific types of cancer, have a very poor prognosis. The complication rate is substantial, the most frequent being dislocation. However, revision surgery is seldom required and prosthesis survival is high.

Reconstruction of advanced periacetabular metastatic lesions with modified Harrington procedure.

The purpose of this study was to assess the outcomes of patients who had been treated by a modified Harrington procedure for advanced periacetabular metastases. Between 2006 and 2013, 16 patients with a mean age of 57 years (range: 28-73 years) were treated using a modified Harrington technique. Extensive (class II/III) periacetabular defects were due to metastatic carcinoma or multiple myeloma. Surgical procedure included total hip replacement and acetabular reconstruction using threaded pins, cemented acetabular reinforcement ring, and/or polyethylene cup. All patients improved in regard to pain and walking ability. Mean preoperative and postoperative Musculoskeletal Tumour Society (MSTS) functional scores were 52.8% (range: 33.3-73.3%) and 72% (range: 56.6-90%), respectively (p<0.05). There were 5 (31%) early or late complications requiring additional surgery. Implant survival was 75% and 37.5% at 12 and 18 months, respectively. Mean survival of the patients was 21 months (range: <1-6 years). Six remained alive, with a mean survival of 27 months (range: 18 months to 5 years). This modified Harrington procedure can be used for reconstruction of advanced periacetabular metastatic lesions.

La tecnica di Harrington

The Authors review the results of 600 cases of idiopathic scoliosis surgically treated by the Harrington procedure. After a brief introductory section dealing with preparation methods, the paper illustrates the technique of the procedure, the various types of mounting, and post-operative care. The Authors assess the improvement obtained in terms of vertebral rotation and of lateral flexion, discussing in particular the need of a correct choice of instrument placement and of an appropriate evaluation of arthrodesis extent in view of avoiding loss of correction. While they acknowledge the value of the Harrington procedure in regard to correction of lateral flexion, the Authors propose further refinements of the original method, to include correction of vertebral rotation and so improve on current results

Modified Harrington Procedure for Acetabular Insuficiency Due to Metastatic Malignant Disease

Extensive peri-acetabular osteolysis caused by malignant disease process is a major surgical challenge as conventional hip arthroplasty is not adequate. We describe a modified use of the Harrington procedure for acetabular insufficiency secondary to metastatic disease in twelve patients. The procedures include application of multiple threaded pins to bridge the acetabular columns, anti-protrusio cage and cemented acetabular cup. Eleven patients were able to walk pain free and achieved a mean Musculoskeletal Tumour Society Functional Score of 80 (range, 68 to 86).

Major reconstruction for periacetabular metastasis: early complications and outcome following surgical treatment in 40 hips.

We performed 40 total hip arthroplasties with pelvic reconstruction in 37 patients with metastatic periacetabular tumor. 3 patients underwent bilateral periacetabular reconstructive surgery and 2 of these had bilateral procedures at the single operation. There were 8 Harrington class I, 7 class II, and 25 class III lesions. A modified Harrington procedure was employed. All patients showed improvements in hip pain, analgesic use, ambulation and mobility postoperatively. 1 prosthetic dislocation occurred after a fall at home 2 months following surgery. 2 patients had pulmonary emboli during the femoral procedure, 1 of whom died during surgery. There were no prosthetic loosenings. Preoperative CT and/or MRI are important for the study of metastatic involvement of acetabular bone. Durability of reconstruction requires appropriate use of acetabular mesh, Steinmann pins, acetabular reinforcement rings and long-stem femoral prostheses. Careful patient selection may improve quality of life. A sequential bilateral procedure should be considered for some patients.

Long-term results of spinal instrumentation surgery for scoliosis five years or more after surgery, in patients over twenty-three years of age.

From 1967 to 1981, 311 scoliotic patients treated at Chiba University, with a minimum follow-up of 5 years and aged more than 23 years, were selected for this study. Seventy-two were males and 239 were females, whose age at operation ranged from 9 to 44 years, with an average of 16.5 years. The operative procedures were one-stage Harrington procedure in 179 cases, staged procedure in 108 cases, anterior procedure in 20 cases, and combined anteroposterior fusion in four cases. Including 198 patients examined physically, a total of 263 patients (54 males and 209 females) have responded to a questionnaire or were interviewed by telephone. In general, 85% of the patients were satisfied with the result of the operation for the control of spinal deformity, improvement of the cosmesis, and increase in physical and social activity.

Anterior cruciate deficient knee, new concepts in ligament repair.

Metastatic bone disease to the pelvis can lead to lower quality of life and function secondary to pain. Historically, treatment was palliative with radiation therapy and chemotherapy used to reduce pain. The Harrington procedure and subsequent modifications improved pain and function. In the subset of patients with complications, this would delay potential life-prolonging interventions such as chemotherapy and radiation therapy. Percutaneous palliative pain procedures including ablation and cementoplasty have been developed by interventional radiology for pelvic lesions and have been shown to be safe and efficacious. Additionally, percutaneous methods of pelvic fracture fixation have been developed. Modern image guidance technologies have allowed an expanded multidisciplinary approach to pelvic metastatic disease in a minimally invasive fashion with combinations of ablation, internal fixation, and cementation to improve patient quality of life and outcomes with decreased morbidity and rapid return to radiation and systemic therapies.

Is the Cotrel-Dubousset really universal in the surgical treatment of idiopathic scoliosis?

We reviewed the results of 22 cases of Cotrel-Dubousset (C-D) instrumentation, 16 cases of anterior approach, and 200 cases of posterior approach by Harrington instrumentation and modifications of Harrington procedure. Posterior spinal fusion and instrumentation by C-D gives better correction and stabilization in thoracic and balanced double major curves. We no longer use the Harrington procedure and its modification. In lumbar and short thoracolumbar curves, VDS is still preferred. In some double major curves combined procedures, VDS and C-D are used to obtain more correction with a shorter fusion area.

Respiratory mechanics in adolescents with idiopathic scoliosis.

Mechanisms causing the reduction in lung capacity commonly found in adolescents with idiopathic scoliosis (IS) have not been understood. In 29 patients with typical thoracic curvatures of mild to moderate degree (less than 60 degrees), total lung capacity (TLC) was a mean 75 +/- 13% (SD) of predicted. The patients could generate only -70 +/- 26 cm H2O (SD) maximal inspiratory airway pressure at function residual capacity, as compared with -102 +/- 28 cm H2O in 21 normal control subjects (p less than 0.001). Studies of lung mechanics in 15 of the patients showed that maximal transpulmonary pressure at TLC was also reduced. Static pressure volume curves were shifted to the right, and both static and dynamic lung compliance were significantly reduced. Although both upstream conductance per TLC and anatomic dead space per TLC were abnormally high, relationships between maximal expiratory flow and static lung recoil were appropriate for age, indicating a normal growth of airway dimensions. From results of the single-breath nitrogen washout procedure, amounts of trapped nitrogen were also normal, indicating that the low lung compliance is not caused by airway closure. After a 5-min period of positive pressure (25 cm H2O) breathing, dynamic compliance increased by a mean of 34% in subjects with low TLC, and by a significantly smaller (p less than 0.05) mean increase of 14% in subjects with normal TLC. The 15 patients were restudied 1 yr after corrective surgery by the Harrington procedure.(ABSTRACT TRUNCATED AT 250 WORDS)